Windows 10

Works on a Core Duo but one of the builds a year or two back dropped support so it can't be upgraded. Want to say 1803 was the last version. There's a rumour that this is fixed in 1903 but haven't tried it yet.

Windows 7
CPU
Useable would be Pentium 3. I have a Pentium M 866mhz laptop and it's workable, likely contributor is XP video drivers only being available for the Radeon Mobility so no DWM to slow it down., I currently have an msata drive installed but previously had a WD 5400rpm drive and it was fine.

Think bare minimum is P2

Memory
96mb

Video
Doesn't really matter as long as you have 2000/XP video drivers and if not the basic display adapter can be good enough.

With the later Windows updates as of 2018? requiring SSE2 though you'd have to be careful with updates but if you're installing Windows 7 on a P3 nowadays likely better off to install 7 in a VM, update and image a HD than install from scratch unless you don't plan on updating.

I once installed 7 on IBM ThinkPad T22 with Pentium III 900MHz, 512MB RAM and small SSD, just for fun. It somewhat worked, but was not really usable.

Just for fun I tried to install Windows 7 on an Asus TXP4 with a K6-III+ @ 500 MHz, but it was taking so long to install that I finally gave up.

About a year ago I installed Win 10 on an Asrock 775 Dual VSTA using the AGP slot, but it stopped working because one of the updates dropped AGP support.

Repo Man11 wrote:

About a year ago I installed Win 10 on an Asrock 775 Dual VSTA using the AGP slot, but it stopped working because one of the updates dropped AGP support.

Yep, they dropped AGP support in 1607.

I got Win10 1903 going on my Pentium M-on-desktop system. It's a Dothan core Pentium M overclocked to 2.72GHz with 2GB of DDR2 memory, and I temporarily put in a GTX 680 to help out with the video. It ran OK, though there's definitely, definitely more system overhead than Win7.

Ages ago, right after Win7 launched I managed to get it running on a P2-400 with 384 or 512MB of RAM. Couldn't get it to work at all on a Pentium MMX-166 with the same amount of RAM on a Super 7 board. I remember reading that Win7 uses the 686 instruction set, which would explain why it didn't work on the MMX.

DosFreak wrote:

Video
Doesn't really matter as long as you have 2000/XP video drivers and if not the basic display adapter can be good enough.

The basic VGA adapter on modern Windows is far better than it used to be, but AFAIK it still does not support sleep and multiple monitors (or supports them very poorly).

dr_st wrote:

DosFreak wrote:

Video
Doesn't really matter as long as you have 2000/XP video drivers and if not the basic display adapter can be good enough.

The basic VGA adapter on modern Windows is far better than it used to be, but AFAIK it still does not support sleep and multiple monitors (or supports them very poorly).

it's also heavy on the CPU,

but form my experience any GPU that isn't WDDM 1.1 or newer incurs a high CPU load on windows 8/10 desktop window manager (at least is my experience with Intel IGPs with WDDM 1.0 vs 1.1)
that being said I have a board with windows 10 with an IGP that doesn't even have windows vista drivers (from p4m890) and it works OK for the very basic with the MS driver.

I think 10 has the same requirements as 8, so it would work on some A64 and P4s from 2003/2004 (needs to have PAE, NX, SSE2)

it also "works" with 512MB of ram, but it's so slow I can't consider that as working,

SPBHM wrote:

I think 10 has the same requirements as 8, so it would work on some A64 and P4s from 2003/2004 (needs to have PAE, NX, SSE2)

This isn't correct. You need more instructions on comparison to Windows 8. More specifically CMPXCHG16b, LAHF-SAHF and PREFETCHW. This is of course true only for 64-bit version.

In similar fashion, I'm wondering if a stripped down, modified Windows XP could successfully run on a 386/486 if you were able to bypass the need for CPUID instructions.

IIRC, Windows 8.1 requires CMPXCHG16b. Windows 8 should be fine.

I successfully installed Windows 7 on an 800MHz Via C3. I wouldn't call it usable - 100% CPU sitting idle at the desktop. I haven't tried it on anything older as yet. I haven't tried anything simliar with Windows 10, the NX requirement stops you from putting it on anything really old or interesting.

Talking about minimum requirements made me think of something... I wonder what it would be like to run Windows 10 on a modest CPU with the smallest amount of RAM possible but with a good fast SSD to use for virtual memory. Something like a Core 2 Duo with 256MB of DDR2 and cheap but fast SSD (like a 256GB Adata SU800).

The SSD would really take a beating, and it certainly wouldn't be fast, but I bet it'd be usable. 😁

absolutely minumum for windows 7 would be using a super socket 7 motherboard with a socket 5/7 processor (AMD K5/K6, cyrix M2 maybe, pentium p54) and no drivers or basic generic drivers, 384mb of ram.

for windows 10 1903, celeron D with EM64T (S775 only i think) or sempron "64" for S754, 384mb for installation is mandatory, or maybe 512mb

if you want the lowest possible but workable with older OS'es drivers, or lowest possible with supported drivers/functions (like aero and such) , things are a little bit different

Windows 7 will boot to desktop with 256MB, but you will need more for the actual installation.

I used Windows 7 on a few P4s and Pentium M era machines. I would stick with XP on a P4 honestly...

I agree. For me, the change from single-core to multi-core happened for me as I moved away from Windows XP and into WIndows Vista. I've never really used a computer running Windows XP that had more than a single-core processor. Vista ran great with a Core 2 Duo @2.4GHz and 4GB of DDR2-800. My current media server is using a quad-core Xeon E5450 modded to work on LGA775 motherboard and 4GB of DDR2-800...and it works perfectly fine. My mother's PC is running a Core 2 Quad Q9650 (essentially the same as the E5450), 8GB of DDR3-1333, and a boot 240GB SSD paired with a 1TB storage HDD and it runs Windows 10 just fine. It started out with a Core 2 Duo and only 4GB of memory and it did actually work, though boot times were 3x longer without the SSD.

My Netbook has an Intel Atom N450 single-core 1.6GHz processor with hyper-threading (giving me only 2 threads) and it's running Windows 10 Home.... but it's horribly slow (obviously). It's so slow, even the SSD I use as the drive isn't really able to help outside of the first boot of the system. To use that netbook for anything, I have to start it up and then wait about 10 minutes for all background shit processes to finish grinding the system to a crawl. It also has only 2GB of DDR3 memory, so that probably has an effect on the system's slowness. Windows 7 Starter wasn't much better than Windows 10. In fact, W10 boots faster at least. I assume this netbook would be perfectly fine if I were to put Windows XP on it and put the old hard drive back in.

What does all that mean? I would say that Windows 10 - to be usable - would require AT LEAST a dual-core CPU and at least 4GB of RAM. Considering that lets you go all the way back to 2007/8, that's pretty impressive. It's also why I like poking around the LGA775 era tech, because they're still relatively cheap and you can build a working system with a modern OS... it just won't play 2019 AAA game titles, as you limit yourself to PCI-Express 1.1 speeds.

Srandista wrote:

Repo Man11 wrote:

About a year ago I installed Win 10 on an Asrock 775 Dual VSTA using the AGP slot, but it stopped working because one of the updates dropped AGP support.

Yep, they dropped AGP support in 1607.

A AGP Card should work in PCI Mode too.
No AGP Driver should be required. its just a "enhanced PCI Slot"
Seems you using some "Special Card" like HD4xxx Series with Bridge Chip ?

the oldest computer I had 7 on was a dell optiplex gx 1 with 768mb of ram, 1.4ghz celeron, 120gb hdd and a fx 5500 pci. Windows 7 ran ok, but nowadays 7 has bug when trying to find updates it spikes the cpu to 100%. For windows 7 a socket 478 p4 runs it good.

Srandista wrote:

Repo Man11 wrote:

About a year ago I installed Win 10 on an Asrock 775 Dual VSTA using the AGP slot, but it stopped working because one of the updates dropped AGP support.

Yep, they dropped AGP support in 1607.

I own an old ATI ALL-IN-WONDER X1900 PCI express, so Asrock 775 Dual VSTA with such card works with last Windows 10 (with 2 GB RAM not 512 MB).