Can I get Windows 95 or NT 3.1 to work on a PC with 640K base, 3072KB extended of RAM, to be more specific. How many megabytes is that by the way? I've tried 95 but it needs more ram it says. Any way to hack it?

it should be 3MB
and honestly I don't see how 95 or NT 3 would work at all

Simple answer.
No.

It requires more then 3mb ram.
You can better try DOS + Windows 2, or maybe 3.0 in standard mode.

Windows 95 needs at least 4 MB of RAM.
Windows 3.1 will work fine.

Windows 95 Needs 6MB RAM, And 80386 Processor.
But Windows 95's minimum setup request is 420KB Memory
I Don't Know For Certain. I Read it On Windows 95's SETUP.TXT

besides DOS (and windows-versions based on it), NT needs at minimum 12mb of ram. maybe it fits into something like 10 or 8 with a lot of fiddling, but definately not in 4 or 3

I worked on Windows 95 on 4mb RAM 386 for a lot of time. Windows 95 more or less works, but 95B even didn't install there.

You would probably have to rengineer the files to make it forced install. Heck, I would be shocked if nashville would work.

I ran NT4 and Windows 95 in 20 MB of ram, so i suppose it would. NT4 didn't like it too much, but i suppose that 3.51 is less demanding. Remember these operating systems were written when ram sticks cost a fortune (600$ for a 16 mb ram stick).

OS/2 did quite well in this environment, until it got to vers 4.

I think you probably need to run memtest on your machine, because it looks like some of the memory is not seated properly.

Memphis Build 1387 worked on the same my configuration (4mb/386dx)

I have a solution for your PC:
Just run HX 2.17 WIP on a dos with LFN.

Ummm what??

Actually, I got Windows 95 to run on 4 Mb of ram but it ran sloooowly. I'm not sure if it can run with 3 Mb of extended ram though it is worth a try. I think that what will happen is that if you try, there might be an error when installing it or after installing it, the desktop will like freeze and all that bad stuff. NT 3.5 needs like 12 Mb of ram though the minimum might just be 4 Mb of ram as well. I suggest you just install DOS 7.1 and Microsoft Windows 3.x. That is your best bet for okay results.

Microsoft stated that windows 95 really needs 8mb,4mb was the develoment goal.

http://www.theosfiles.com/os_windows/ospg_w95.htm

RAM 4 MB (8-16 MB recommended), though I tried it on a VM and it seems to error. 5mb works.

Well, I used the original retail version(floppy disk form), that could be why since its the oldest version of Windows 95 RTM.

Back in 1995 I ran Windows 95 on a Hyundai 486 SX/33 with 4MB RAM (and a 230MB hard drive). It was okay, really, although I didn't do anything too stressful with it, just playing games. I recall that streaming a CD-quality WAV file from the double-speed CD drive was as far as you could go, if you tried doing anything else at the same time it would cause stuttering.

PC Plus (a UK magazine) said in its Windows 95 review that the goal was to give equal performance in 95 as in 3.1 on a 386SX with 4MB RAM and to that end Windows 95 uses a different kernel if you have less than 6MB of RAM total. (I seem to remember that if you went into the Performance tab when running the low-memory kernel you'd get a line advising you to install more RAM).

I ran windows 98se in 16 mb, quite successfully, but this was by running 98lite over the thing, and installing ie separately.

In the main, for a box of 16-30 mb range, i would look at operating systems typically in the 1994/5 range: windows 3.1, windows 95, os/2 3.0, winnt 3.1. Later operating systems are a bit of a soak.

I've had 95 run in 4M of core, but it is painful. Even 3.1's painful with that little.

Just put an old DOS on it and learn man-computing.