It won't work if you kept it in your cellar - rust. :P

My father had an '89 computer but he must have upgraded because it could smoothly ran Win 95. Unfortunately I can't remember the specs

That was the 486 era so that's probably what it was. Windows 95 will run fine on them if there's enough memory.

I remember my first game Pacman and my second Tetris there.

For some reason, I can't get my HD get recognized on my comp. Boots fine with a boot disk, but is unable to reach C:\ I formatted it using Dos's Format and it now has a FAT filesystem. System itself's P1, 100MHz, some RAM (dunno how much exactly, just filled up the slots and got it to work), 600MB HD, cd-rom drive (which doesn't seem to want to boot either, or skip it when it's got nothing to boot from) and diskette drive. BIOS recognizes the HD, but booting doesn't. Tried the Abandonia bootdisk and one I made myself, but neither work. Anybody know what could be the problem?

Did you mean that you can't install windows on your HD? If that's a problem then try this: after writeing "format c:" write " /s" so that should look like this
C:\>format c: /s

Did that. HD gets recognized now though. Was a jumper problem. Now both diskdrive and HD work fine, but can't get the cd-rom drive to work yet. Says something 'bout not being ATAPI compatible. Also ought to get it from Qwerty to Azerty, but it's been years since I've done that and I'm afraid I lost that little touch.

When CD-ROM drives first began to appear there were some proprietary models that had to be plugged into a special controller card. Panasonic, Mitsumi and Sony are the only ones I am aware of. If you happen to have one of these you could get a card on eBay to connect it to. Personally I would just install a modern CD-ROM drive; they are dirt cheap and that way you won't have any trouble reading CD-R media. :)

Creative Labs here :P

Oh yeah, Creative Labs also made a proprietary CD-ROM. I think it plugged into one of their early SoundBlaster cards. However it's probably more likely that the controller on your motherboard does not support ATAPI drives or there is actually something wrong with the drive itself. Also could be the drivers you are using; what are you booting up with? Try a Windows startup disk if you haven't already.