The original versions of Microsoft Windows were basically a "graphical shell" that ran on top of MS-DOS, and typically the computer did not boot to those. Windows, I believe in this early period, was more like an application looking for a purpose than some purpose looking for a GUI interface application. That's why most people ignored Windows until 1992 or later, because the majority of comptuer users were seasoned pros at using the MS-DOS CP/M derived command line., so Windows failed for it's first 2-3 versions. In the early 1990's thouggh, with the advent of the internet and "computers are the future" being a part of education Windows was seen as a way to get the computer illiterate to figure out how to use an IBM PC more easily. It meant they did not have to train future employees not hired for I.T. related roles how to use commands like "dir" "CD\" and how BAT/COM/EXE files can be run. Since standalone software could be installed, and manifest itself to Windows as a "program item" - a singnle icon in a "program group"/MS-DOS Executive/Desktop, they did not need to teach the user more than how to click on a mouse. It made things cheaper and easier (albeit slower).

Windows 95 was truly the beginning of the "modern" Windows. The familiar Start/Taskbar/System Tray layout with a wide-open Desktop above it became standard from that point on, as did the PC booting directly into Windows from Startio (prior to 95, all Windows installations booted directly into DOS, and then you typed "WIN" at the command line to kick off Windows).

Windows started getting good during the "Windows 3.1x era". These were still 16-bit Graphical shells that ran on top of MS-DOS but Windows 3.1/3.11 + For Workgroups were all the first time Microsoft really put any real effort into making them a usable user-environment beyond a mere graphical shell for specialized yet castrated Windows apps and DOS applications. At the top, end, Microsoft now offered proper networking over various protocols and topologies through Windows, albeit using the underpinnings of Microsoft LAN Manager/Network Client 3.0. SVGA Graphics were availible for the first time, allowing for "Darn near photorealistic (256 color)" images on SVGA compatible PCs - and were advertised through a 256color.bmp wallpaper provided (honestly marble.bmp is still my fave). Screensavers came standard to prevent burning in your CRT monitor, various features such as APM for Laptop computers were provided as well. Windows3.1x was the first version to get on the internet, and in 1994, WIN32S allowed Windows NT and some WIndows 9x applications to work with 3.1x. The 3.1x era runs from 1992-2001, as many of these systems stayed running well past the dawn of the new millennium.

The Windows 9x era runs from 1995 with WIndows 95', through Windows 98 Second Edition in 1999, but carries on until about 2004-2005 or so. Windows 95 was a big deal at the time and a step up form 3.x by basically creating the interface we users have been using in Windows and even some Liunx distros ever since - that familiar "Taskbar" at the bottom with a "start Button" and a "System tray" hosting status icons for networking, volume, various resident applications we might need a "ticker" for, and of course the clock/calendar. This layout has been ubiqutous ever since. Windows 95 introduced us to a more "Internet Focused" O/S with more focus on gaming as well with Direct X. The ghosts of 95 still live everywhere in major civil services such as your local Police Department, Fire Department, or Hospital through the development of Active X control web apps in the 90's now causing us headaches today with Microsoft Edge and other Chrome-A-Likes. The 9x era drew to a close when the "Modern" era came in.

SCREENSHOT	VERSION(S)	IDEAL SYSTEM	POPULAR APPS	DESCRIPTION
WINDOWS 1.x (1985)	Windows 1.01 Windows 1.02	i8088 512K RAM min 2.4MB HDD Spc. 360K FDD Mono/CGA/EGA/HERC	Can't think of ANY popular applications for Windows 1.x	Windows 1.x did not sell too well but it's most famous moment was the re-surfacing of a commercial on YouTube in the 00's of a hyperactive Steve Ballmer going on one of his famous rave-fests about Microsoft Windows showing the "incredible" feat of copy+paste a picture of the car from Miami Vice into a Windows Write document or somesuch on an IBM PC AT. Today this would be a subject of much riducule but back in 1985 it was amazing to see a picture of a car that looked even remotely real on a computer monitor, let alone be able to move that car between 2 different programs without some serious screwing around to get it there.
WINDOWS 2.x (1987)	Windows 2.01 Windows 2.03 Windows/286 Windows/386	i8088 i286 (W286) i386 (W386) 512K RAM min 2.4MB HDD Spc. 360K FDD Mono/CGA/EGA/VGA/HERC	Still can't think of an imporant or influential application. I do know there were some early Voyetra Sequencer releases for Windowos 2.x, as well as I had a weird old Fractal Trees program for it a long long time ago.	Windows 2.x never really gained much attention in it's original time either, as people were still not sure what benefit a GUI would bring to their MS-DOS controlled PC. This was around the etime the Apple/PC rivalry really started to get off the ground, with Apple users saying "I don't have to f*** around so much or learn a bunch of gibberish to use my computer" while PC users were all saying "I'm a REAL computer user because I can actually use those COMMANDS to run my machine and actually learn them, and my computer is designed for WORK, not playing with music and dpretty pictures like your Trendy Apple toy!". Of course, we can all laugh at the PC as well for that atrocious and super-cringey Windows 386 rap commercial they made with the woman dressing like a Spy as she obsconds with some files from her Compaq Deskpro 386.
WINDOWS 3.0 (1989)	Windows 3.0	i8088 640K Minimum 6MB HDD Space Floppy Drive Herc/CGA/EGA/VGA Video	Microsoft Excel Microsoft Word WordPerfect Microsoft WSS	Windows 3.0 was when Windows started to get a bit more attention by having it preloaded on certain computers at the time. That said, though, it still did not go as far as Windows 3.1x did. Multimedia required a "Windows Sound System" add-on for sound, Networking was still done at the Real-mode DOS level with LAN Manager or LAN Client (or Novell Netware, or whatever else they had). I call this one the Calm Before the storm.
Windows 3.1 (1992)	Windows 3.1 Window For Workgroups 3.1 Windows 3.11 Windows For Workgroups 3.11 Windows 3.2 (Chinese)	i286 (3.1) i386 (WFW) 1024K RAM 6MB HDD Spc FDD Mono/CGA/EGA/VGA	WordPerfect 6.1 Microsoft Works Microsoft Office Netscape Navigator MSIE 3/4/5.1 AIM mIRC Corel Draw Adobe Acrobat Adobe Photoshop Aldus Pagemaker Circuitmaker 6.1 Norton Desktop AfterDark 3.0	Windows 3.1 was the first major version of Windows to actually catch on. Even then, it was not THAT widespread. Windows 3.1 typically shipped on a 386 SX/DX/SL or 486 series machine brand new back then, and I'm sure at least a nice chunk of the user-base never realized it was Pre-Loaded until much later if the maker did not put "WIN" at the end of the Autoexec.bat file. Between releases, Windows 3.1x grew from being almost like 3.0 with Multimedia support wrapped in, into being something like a 16-bit Windows with Windows 95 functionality as For Workgroups 3.11 could - to this day - be connected to a broadband intenret connection using the TCPIP32B add-on driver, and a nice ethernet card. This is also when games for WIndows became more widespread with Debris, Hyperoid, TDK Pinball, Hugos House of Horrors, 221B Baker Street, as well as Sierra making tehir own version of the SCI interpreter to run thheir DOS games in 3.1 with full sound and graphics - such as Kings Quest V or Freddy Pharkas - became commonplace.

SCREENSHOT	VERSION(S)	IDEAL SYSTEM	POPULAR APPS	DESCRIPTION
Windows 95 (1995)	Windows 95 Windows 95 OSR1 Windows 95 OSR2 Windows 95 OSR2.5	An intel Pentium 90 or 486 DX4-100 machine or better with 16MB+ of RAM, a 2+GB HDD, and SVGA Video, with a modem, soundblaster compatible sound card, and 2X+CD-ROM drive	Office 97', MSIE 3/4/5, Netscape Navigator 3/4/5/6.x, Microsoft Encarta, Microsoft Money, AOL Instant Messenger, WinAMP, DOOM95, Quake, GTA, Red Alert Command and Conquer, Descent, Descent II, The Curse of Monkey Island, Midtown Madness, Microsoft Flight Simulator 5	Windows 95 kicked off in early 1995 with a massive advertising campaign licensing music from the Rolling Stones - "Start me Up" - to sell their new O/S. People immediatley liked the new, cleaner, easier to use interface, and it's internet-centric focus compared to clunky old 3.1. It was the perfect storm at the perfect time: The internet becoming mainstream, making PC's mainstream, driving Windows 95 to become mainstream, and these three things standardizing and forever changing the face of what then was still called the IBM Compatible PC. However, not all was perfect as new technologies such as USB and Plug'n'Play were problematic in these early times, and the high resource requirements for a stable system - what I just listed - frustrated long-term-PC-users like myself to no end, as we now had to go out and fork over $1500+ for a brand new "budget" 486 DX4 system, or more mainstream approved, Pentium system in the 75+MHz bracket which would be upwards of $2000. It also was heavy on HDD space too, Windows 3.1x took up 8MB of space on a typical 250MB-2GB HDD of the day, but Windows 95, it used up an entire 150MB just for a BASE LEVEL installation - eating up over 1/5th of your 528MB HDD on an older 486 system. It was so bad a comedian made a video about it based around "Start It Up" with lines like "It's Windows 95, I need a new hardd drive, It makes a Pentium Fly ....My 3-8-6, ain't got the speed, I gotta get myself a brannnnd new machayinnnnnnnneeee".
Windows 98	Windows 98 Windows 98 Second Edition(SE)	Intel Pentium 100 or faster with 16MB of RAM+, 56K Modem, 250MB HDD space (so 4GB+ HDD), Sound Card, SVGA or 3D Accelerated Graphics	Office, Works, Money, Encarta, IE 4/5/6, Netscape 4/5/6, Quake, Half-Life, Diablo II, The Sims	Windows 98 came out in 1998 and while 95 was criticized for it's high resource usage it was beginning to become obvious the "Bloat" was here to stay. Now 98 came with MSIE 4/5 BUILT IN as a part of the Windows explorer graphical shell, eventually prompting a Anti-Trust Lawsuit in both America and Europe over anti-competitive practices in the software industry. In America this was settled more peacefully, but In Europe it lead to IE being removed. Windows 98 SE is the best version of Windows 9x you can get, as it was released AFTER Millennium Edition (Me) to address concerns about Windows Me.
Windows Millennium Edition (Windows "Me")	Windows Millennium Edition (Me)	INtel Pentium II, 32MB RAM, 8GB+ HDD (uses up almost or more than a Gigabyte of Space in large installs), Sound, 3D Accel	Office, Works, Browsders, etc....you know, the usual for the late 1990's	Windows Millennium Edition, supposedly supposed to be pronounced "Me" not "M-e" like a lot of people do, was the version of Windows Microsoft was claiming "DOS is Dead" over. Truth was, this was the same as the rest of the 9x series with DOS still included with it, but all sorts of nefarious cover-ups done to hide the fact there was still DOS hiding underneath the beast that was Windows Me. When it was released, it was notoriously unstable, buggy, and had a lot of problems, earning it the same horrid reputation put with Windows Vista almost 10 years later. However, in recent years, it's gained a bit of a reputation of being a pretty good O/S for late 90's PC builds since hte internet is no longer targweteing it. A common fact most people gloss over or forget was this was the "home edition" counterpart of "Windows 2000 Professional" - aka NT 5.1.

SCREENSHOT	VERSION(S)	IDEAL SYSTEM	POPULAR APPS	DESCRIPTION
Windows NT 3.1	Windows NT 3.1			Designed in the image of Windows 3.11 for Workgroups, NT 3.51 was the first NT-based Windows. Windows NT, at this stage, was primarily Enterprise focused and thusly not very widespread. In my whole time of collecting vintage computers, I have yet to have seen a single device with this installed on it.
Windows NT 3.51	Windows NT Workstation 3.51 Windows NT Server 3.51			Windows NT 3.51 was redesigned to work as an enterprise version of Windows 95 - as obvious by the move from a 32-bit PROGMAN.EXE to the Explorer.exe interface, which I believe YouTuber David Plummer had a hand in converting it over to. Again, it did not see a lot of use outside the office and thusly is not exactly a good candidate for any gaming-centric retro-PC builds.
Windows NT 4.0	Windows NT 4.0 Workstation Windows NT 4.0 Server			Windows NT 4.0 was like the 98 SE of the NT line. IT was held in high esteem and designed to be more like Windows 98, but was far more stable and reliable. However, again, it still had not caught some foothold in the home market at all, so nobody really saw it outside of work, but it was well known as being a good Enterprise O/S and is slikely a big part of why we still use Microsoft Windows in corporate environments until this day.
Windows 2000 Professional	Windows 2000 Professional x86 Windows 2000 Professional PPC Windows 2000 Server Windows 2000 Professional RISC	i486 16MB of RAM 350MB of HDD Space CD-ROM SVGA Modem or LAN for Updates		Windows 2000 Professional was the NT Equivalent of Me, but unlike ME, it was an excellent O/S off the bat, and shared two traits with Windows 3.1x in that it helped popularize the NT Kernel based Windows as some people bought this for at home - just like Windows 3.1, and also just like Windows 3.1, it enjoyed a very long shelf life because it was solid, reliable, a bit more secure than previosu versions, and was just a good, basic, reliable workhorse. If you're looking for a good NT Version, I'd suggest 2000, specially if you are running something as old as a 486, as it can be tuned to run some XP class software.

SCREENSHOT	VERSION(S)	IDEAL SYSTEM	POPULAR APPS	DESCRIPTION
Windows XP	Windows XP Home Windows XP Pro x86 Windows XP Pro x64 Windows XP Ultimate Windows Server 2003	Pentium 32MB min 350MB Spc CD-ROM Internet	MSIE 6 Microsoft Office XP Microsoft Works The Sims Skyrim GTA III GTA Vice City GTA San Andreas mIRC Limewire Kazaa LiveJournal FCEUx ZSNES Halo Bonzi Buddy IE Toolbars AOL 4/5/6 AIM MSN Yahoo!	Windows XP was the last version of Windows to be dominantly 32-bit (x86), and was also one of the longest used and most enduring, with a shelf life of 12 years, with support ending in 2013. Windows XP was solid, reliable, fast, it had a few Security scandals ealry on and some serious teething issues, and the designer interface is bloody ugly ("Windows Fisher Price" we used to call it), but XP is one of the higher up levels of vintage Microsoft Windows more ideal ffor a circa 2001-2004 gaming machine. It was also the first version of Windows to be 100% on NT in it's day, with special editions being HOME, PRO, ENTERPRISE, and ULTIMATE, all in the x86 (common) and x64 (rarely used) versions, as we had not quite made the jump to 64-bit yet.
Windows Vista	Windows Vista Home x86 Windows Vista Pro x86 Windows Vista Pro x64	Pentium II 128MB 1.5GB Spc 8MB GFX CD-ROM USB	Windows Vista had a very limited use period because Windows 7 massively eclipsed it. What's sad about Windows Vista, is that it was one of those "edge case" OSes like Millennium Edition was, and sort of get's the "black sheep" treatment for the same reason.	Windows Vista had a bit of a scandalous and interesting beginning. ARound 2005, Microsoft claimed they were ditching the entire original Windows NT codebase and working on a new project called "longhorn". Windows Longhorn was what eventually was scrapped and became Vista. Due to it's isses with resource usage, security holes, and so on, despite being availible for free to "hackers" with an offer of $10,000 for anyone who could hack the O/S.
Windows 7	Windows 7 Starter x86 Windows 7 Home x86 Windows 7 Home x64 Windows 7 Professional x86 Windows 7 Professional x64 Windows 7 Enterprise x86 Windows 7 Enterprise x64	Pentium 4 2GB RAM 15GB HDD Space 2MB GFX	MSIE 7/8/9/11 Firefox Chrome Office 2003 Office 2007 Office 2010 Office 2019 Call of Duty The Sims 2/3 Crysis	Another long-run Windows, like 3.1, 98 SE, 2K, and XP, was Windows 7. Windows 7 was when the x86-x64 crossover began to take hold, with more 64-bit installations coming later, and support for (U)EFI being rolled into the O/S, allowing for less partition waste using GPT partitions among other things. It also was the beginning of widepread use of Bitlocker drive encryption in enterprise environments, whereas previously you had to have a 3rd party product like Sophos to do that for you. Windows 7 officially reached end of life in 2021, with paid extended support from Microsoft continuing up to 2024 for Enterprise users and rich people. 7 is a great O/S to use for a tweener because it actually allows you to plug later era ATA HDD in via USB and write DOS and Win9x installs to them via drag'n'drop, which I STILL use Windows 7 for.
Windows 8	Windows 8.0 Home/Pro/Ent. x86/x64 Windows 8.1 Home/Pro/Ent. x86/x64	2GHz CPU 2GB RAM 10GB Space Internet	MS Edge (NC) MSIE 11 Office 2013 Office 2019 Office 365 Chrome Firefox	In 2013, the PC Industry was in trouble, sales of PCS were down, and sales of touch-screen mobile devices were up. Not sure if Microsoft remembered Windows for Pen Computing circa 1992, or if they forgot, but I do know it wwas almost like a coming-back-around of the attempt to get people into Pen/Touch/Tablet PCs at the time. The interface was redesigned to be consistant with the failed "Windows Phone" product - a WIndows-based Smartphone - eliminating the taskbar and start button at first, which the button and bar were returned in Windows 8.1 by user request, but the Start Menu was still replaced with the "Metro" or "New Style UI" that Windows used that had it's own special applications in special tiles designed to work and be used like a touch screen phone application. Microsoft Edge was a part of this rollout, though under an entiretly different codebase at the time.
Windows 10	Windows 10 Home Windows 10 Pro Windows 10 Pro for Workstations Windows 10 Enterprise Windows 10 Enterprise LTSC Windows 10 Education Windows 10 Pro Education	2GHz CPU 2GB RAM 10GB Space Internet	MS Edge (NC) MS Edge (Chromium) Firefox Chrome Office 2013 Office 2019 Office 365 Five Nights at Freddy's 1/2/3/4/SL/World/etc. Slenderman	Windows 10 was released in 2015 to return to the standard Windows Form, though the "touch/pen" features were still available as a user selected option. Windows 10 was an interesting release over time, as it was more like a "rollercoaster" than an easily pinnable "dung heap" or "massive success" on Microsoft's part. Part of this was because it had rolling "Builds/Revisions" based on numbers such as 1803, 1909, 20H2, 20H1, instead of Service Packs or Official Service Releases like NT/2K/XP/7 or 95 respectively. Windows 10 is still current but it's when we start to lose more and more legacy features such as support for FAT-16 formatted drives, and the ability to read hard disk drives with DDOs on them. It also was the era when the changeover from the old BIOS Int13h boot scheme used since the original IBM PC in 1981 was replaced by the Universal Extendable Firmware Interface (UEFI) used these days, with a GPT (General Partition Table) hard drive scheme that wastes less space with management data, allowing for more usable space from the unformatted space on the drive.
Windows 11	Windows 11 Home Windows 11 Pro Windows 11 Pro for Workstation Windows 11 Enterprise	2GHz CPU 2GB RAM 10GB Space Internet	MS Edge (NC) MS Edge (Chromium) Firefox Chrome Office 2013 Office 2019 Office 365	Windows 11 was released in early 2022, and is the latest version of Windows by Microsoft. The major changes once again included an attempt to move to a new style of UI, this time mimicing the Dock Bar from Apple, which was lifted from a *nix distribution stylistically. It also *requires* a TPM as user workstations are now being locked down by Microsoft Bitlocker (the keys for which are stored on your mandatory Microsoft 365 profile for recovery purposes). The new UI design aims at changing the appearance to look different, and get away from Legacy code. It's looking a lot like this will be another edge-case Microsoft version like ME and Vista that nobody will use in the future except curious retro people (assumkign you can even activate it, all Microsoft Windows activation is done online using a code with limited uses to prevent piracy - or a code burned into the BIOS of the computer (which you don't have to enter).

First off, I would avoid Windows 1.x/2.x/3.0. 1.x and 2.x (+286 amd 386) don't have enough useful software, games, or capabilities to be useful for anything, and most of their EXEs can be run properly on a bog-standard Windows 3.1x system without any modification. There's just no point to these at all. It was fun when I had a IBM PS/2 Model 30 286 that had Windows 286 on it, but that computer became tremendously more fun and useful when I wiped Windows and used that large portion of 20MB for something else - DOS Stuff.

The lowest I'd ever go is Windows 3.1x - and this largely depends on what/how the system is being used. Bog Standard Windows 3.11 is usually what I used on computers that don't connect to the internet or my network, like my FMA3500C laptop which has no way of connecting ot anything right now. But most of the time I tend to prefer Windows For Workgroups 3.11 because while the network support is minimal and not a lot of the internet works with it (really should make a Win16 version of Links for it, lol) you can use IRC, AIM Phoenix, and a lot of other stuff, and Opera 3.62 DOES work in Frogfind, plus FTP and basic Fileshares (behind a firewall and highly restricted mind you) will work. Seems it uses SMB 0.1, LOL.

When faced with the 9x Series, Windows 95 OSR 2.5 and Windows 98 Second Edition are the best! - Even a decent 486 DX2-66 with a lot of RAM runs fairly great under 98 SE, and can really scream if 98 Lite is used. 98 Lite was a package that removed the integrated IE crap from 98/98 SE and replaced it with libraries from Windows 95 to make the O/S lighter in weight, faster, and overall, allowed it to be more user-tailorable. I find a 486 with 32MB of RAM on 9x can really rip, and anything faster is "child's play".

I'd avoid all of the NT Versions except 2000 or XP. If you have a 486, and REALLY want NT, use Windows 2000 Professional x86. It won't be super fast, but it's surprisingly fast considering how heavy that O/S actually is (it's like an XP-Lite). But Pentium or newer will do better with Windows XP. Both of these can be brought fully up to date using the Legacy Update service. Just remember with XP, you will need to break the Registry Key, use Legacy Update, and then use oobe/msoobe /a to activate it, since XP was a real PITA with it's activation.