Hi everyone!

TLDR.: IDE drives and FDD not liking each other, random errors and freezes. Bad PSU?

I recently did some minor upgrades for my Pentium III build when I decided to get a newer GPU (An NVIDIA GF 6200) which is still supported in Debian 9.
I originally set up a Win98SE and Debian 12 dual boot for this rig. However no matter what driver or GPU I tried, graphics drivers for Debian just wouldn't work.
I also installed a bunch of random stuff onto Win98SE like kernel ex, regtweaks, stuff from Win ME, unnofficial service packs, etc.

Surprisingly, although slow, Debian 12 was much more stable. Under Win 98 I constantly got: total freeze when loading onto the desktop or shortly after, failing to copy or access files from my USB 2.0 card, EMM 386 (or what it's name is) not being able to load properly, and warnings about the PCI bus and the A20 line. And thus, I decided to reinstall the whole system.

After managing to remove grub and wipe the drive, I eventually resorted to using a different pc to start the Win98SE installation, and finishing it up on the real deal. After a couple of hitches, the install succeeded and now I have a clean WIN98Se install. (So clean, that I forgot the USB mass storage drivers...)

After a reinstall I thought that the problems would start going away (because of how stable Debian was), but I was mistaken. Every time when I would even highlight the A: drive, Windows freezes. Sometimes I get warnings about drive C: or just programs running not responding. Almost as if the system clock has been dropped, like a turbo button, or something.

Even before then, if the HDD was detected the floppy drive would not usually work properly, making squeaky noises doing so - but running fine if no hdd was detected. I also had similar issues with CD and DVD drives, (and my have bad trays that like to not open), so unplugged them a while back.

At this point I only have a couple of suspects of what can be wrong:

• Bad PSU
• Bad IDE/SATA adapter
• Some PCI cards interfering
• Or chipset south bridge going haywire

(Specs:
P3 slot1 550 cpu
Fujitsu/Siemens s26361-d1107 Mobo with intel 440BX
640 mb ram
Mx400 gpu Geforce 6200
Some older generic psu (main suspect?)
Kingston sata ssd w/ Logilink bidirectional ide sata adapter, limited to 120GB
Cd drive / dvd drive (I tried with both)
Sb220 sound blaster live 5.1
Logilink 5port USB 2.0 card
Some Austrian or German PC case)

I haven't installed Debian 9 yet, and I am also considering Win 2k or XP as a third OS. But I think I will not do anything else until these issues are solved.
(I'm considering if I can get a faster CPU somehow, like on a slocket adapter. I could also go for a later P4 pc, as sadly I don't really have ISA sound cards, which would be the prime reason this PC exists. Not to mention, not having SSE2 under Debian was big sad)

I think I will try to get another PSU to see if that helps, although I only have a couple other really old and bad ones. I'm also told that newer ones are usually missing or have weaker non 12V rails..

Previous topics:
Part 1: Pentium III restoration - help wanted (bad USB port, system hangs, quickly draining CMOS, etc.)
Part 2: Fixing a not working USB port (on a PIII)