All right... the bios upgrade failed - I have downloaded v 3.8 bios. Awdflash does report the correct checksum, but it sais: unknown flash type.
I have for sure the 7T mobo (boot message)
I have checked the CPU temps as well:
CPU: constant at about 48C°
VCore 1.76V
VDD: 3.32V
3.3V 3.35V
5V 4.97V
12V 11.88V

I'm not sure whether this is ok (12 mV isn't a lot, but I don't know how picky my hardware is)

There's a few tweaking lines you can add to your system.ini file that will tune up win98, and may help a bit. They help in preventing excessive swapfile usage, and tune up the video performance, among other things. They are best used on systems with more than 128MB ram- you didn't say how much ram you have. I'll send them if you like- very easy to do- just a few lines added to a notepad file in win98.

There's probably similar tweaks in Linux, but I'm not that knowledgable yet to recommend anything.

Just saw your last post with the specs. The 48C. cpu temp is too high- I would think about better cooling. Anything over 45C. is potentially a source of weird problems like yours. Maybe you could get away with a super fan replacement on your present heatsink, but the noise will be VERY loud. If you replace the entire heatsink, make sure it will fit your board before buying.

The 3.3v and 5v line are pretty good for the voltages but the main concern is the combined wattage on these lines. For example, my 420w has a combined 245watts 3.3 and 5v lines. The PS should have a label showing the amps on each line. 3.3 needs to be 20A, and the 5v needs to be 30A. Less will be problematic. The 12v line while seemingly lower that specs, is not that serious, as that mostly runs fans and drives.

Bottom line- I'm now thinking you need better cooling- both in case airflow, and the cpu heatsink. even better case airflow and exhaust will drop the cpu a few degrees too. Case modification is an option (blowholes, etc.) I put a square duct hole in my case side and constructed a little cardboard duct directing outside air to the cpu fan, and my cpu temps dropped 7C. immediatly.

All right.... better cooling then - I read in a magazine that there are water-cooling systems. Kind of expensive, but very silent, ie no noise at all. More airflow... well, not the easiest thing to do with my tower, but i'll give it a shot. Another fan inside the case might help as well?
Oh, and ram: I have 256mb sdram. They were set to run at 100 (133 chips). I set it to 133 and I didn't notice any difference in temp/instability.
I can't see the PS specs at the moment - i'll repost after another opening of the case
Your help is a lot appreciated!!

I'm sitting in front of my second box...I noticed a bad thing:
The fan "throws" the air directly onto the PS, the distance is only about 3cm large... I'm not experienced, but I think this is not good at all, so I'm with a new case as well
The PS seems to be low...
3.3v:16.0A
+5V:25A
+12V:13.0A

I just started the PC with opened case: the CPU temp is now at 35C°

If the cpu temp stays around 35-40C (down from 48C.). after some time and use with the case open, that's a good indication that the case airflow is not up to par, and the heatsink on the cpu is doing a reasonable job. I would leave it like this for a day or two, and see if your problems go away. If so, you've found the source of them.

If cpu temps rise to 45C. or more, try putting a small floor/room fan blowing gently into the open case (if you have one), and checkingthe temps over several hours.

The amps on your 3.3 and 5v lines are typical for cheap power supplies, and may or may not be adequate- it depends on the total combined wattage of those two lines, which can vary from manufacturer to manufacturer, and how many other drains on the PS you have, like cd-rw drives, pci cards, etc.

I'm not sure what you mean by this:
"The fan "throws" the air directly onto the PS, the distance is only about 3cm large..."

Is the PS fan mounted on the outside of the PS, and directing air into it? If so, this is good. Some really cheap PS's have it blowing the PS hot air INTO the inside of the case, which is insane! You want to eject all possible hot air out of the case, and have cooler outside air getting inside to dissapate all possible heat from the componets. This is why my outside duct to the cpu fan works so well.

Clarification- I mean is the fan mounted inside the case, but actually onto the outside of the PS, blowing air into the PS, and then ejecting out the rear of the PS to the outside.

Or, is the fan actually inside of the PS itself, and blowing hot air INTO the inside of the case? This would be extremely bad for the case air temps, and thus also the cpu temps. Almost all PS's with a fan inside blow the air out of the case.

One other thought- at some point, you need to ask yourself how much money you're willing to put into a somewhat obsolete machine to solve these problems. You might be better off putting the money into a better motherboard/cpu combo. But if you can get the problems solved with a little cooling modifications, then it would be worth the trouble

Hmm... the fan of the PS looks out of the PC, not inside, seems to be a good thing.
What I mean with the CPU fan:
The CPU fan blows its air directly on the PS. And the distance between the PS and the CPU fan is about 3cm. It's like the air beeing blocked at the PS. Actually, the PS is open at the point where the air is coming from the cpu fan, thus cooling the PS as well... I'm just not sure whether this is a good thing.
The thing is with the better CPU/Mobo, that i still have to buy (I do?) a new PS with 300, preferred 400 Watts, a better cooling. New CPU or not, the problem would probably remain. But I'm considering a new CPU/Mobo, but as I said, I won't get around buiing either better cooling system, better airflow and PS replacement.... I just need all the options and then i'll decide a suitable solution.
Yet another thing is, that I cannot figure how much power my devices need. The CD-rom has been replaced by a very old, which I have no documentation from, and the case doesn't state something usefule, except: +5V--0.9A +12V--1.5A, but nothing about watts.
In order to use my Win again, I'll have to reinstall it, thus overwriting the mbr....
Unfortunatelly, I don't know how to figure the combined wattage... i'll just state the rest that's written on the PS:
FUSE RATING:6.3A,250V (+3.3V & +5V=150W max) (+3.3V & +5V & +12V=230W max)
I have to leave my home now - i'll be back in about 4 hours.

Ideal minimum for a newer system (especially amd) is 1 thermal fan blowing in, 2 thermal fans blowing out. That and a 300w power supply (min). If you don't have a bunch of extra drives, devices, and gizmos plugged into that ps, it should be adequate and affordable. And if you're not up to the pepsi challenge (aka finding out how much power each individual component draws), the 300w should work.
As a rule of thumb, if you can spare a few extra bucks, then more fans/cooling + higher watt power supply + UPS + backups = more redundancy = safer system and fewer catastrophic failures.

OK- I take it you have a regular PS, with the fan inside of it, and pointing the air out the rear of the case.

You never mentioned the cpu fan on top of the heatsink. If I understand you through all your posts, you seem to be saying that the fan mounted on top of the cpu heatsink is blowing away from the cpu and heatsink. This is totally wrong. It should be blowing it's air downward directly through the heatsink onto the base that contacts the cpu. If it's not, somebody put the little fan on downside-up, and this will drastically reduce it's effectiveness. Solution: Just flip the fan over and reattach, so the air goes down onto the heatsink and cpu. This alone should be worth a 8-10C. drop in cpu temps.

Have you got any case fans? Preferably mounted in the front lower part of the case, with access to the outside air, and blowing that air into the case.

Your PS wattage seems typical for that type PS. Not the greatest, but decent for a 230w supply. Cd-roms typically use 15-20watts.

Sorry, I made a lot of confusion - the fan is mounted properly...
I ran the computer in Win with opened case and playing several games for a longer period of time and I didn't get any crash. The real problem with win really comes from the CPU heat, or the heat of other devices. I don't have a case fan. That's what I have to change, probably.
I'll see how I can achieve this..
BTW... do you mean a fan on the back side of the pc? I don't see any way to mount a fan on the front side...

Would it be possibel, that the problem reported http://www.linuxquestions.org/questi...ht=nvidia+sax2
might be cause by a too weak PS?

I mean inside the case, on the front bottom area. Most cases have a place to mount an 80mm fan, blowing outside air in, located there.

Another trick is if you have an empty top bay available, remove the plastic covering, and it will serve as a blowhole at top, allowing the hottest air to escape faster, especially if you install a case fan at the bottom. I just mounted my cd-rw in the second from top bay, and popped out the top bay's plastic cover. The cooler the case air, the cooler the air the cpu fan has to use, and that translates to cooler cpus, and less weird problems.

I looked at the link for the video problem. I can only say a weak PS can cause many we looked at the link for the video problem. I can only say a weak PS can cause many weird problems, just like too much heat. Then again, this could be a video driver pird problems, just like too much heat. Then again, this could be a video driver problem unrelated to hardware.

sorry about the extra typo sentence "I can only say a weak PS can cause many we looked at the link for the video problem."

You're right, there is a place to mount an additional fan inside the case, at the bottom. My concern with this one is, that the plastic covers most of the are, where the fan is located. There are some blowwholes at the bottom.
I hope this is enough...
About the problem with my video card: I have written an Email to NVidia. What I figured, that the computer stops responding when it tries to set the resolution (1280*1024)
The resolution is supported, no problem here, but it is the first time the driver is using an interrupt. May be, the chip now starts up eg, power requirement increases fast, thus freezing the system.
He told me to check whether there is an IRQ conflict. I wasn't sure how to check but in Windows, there is no Problem at all, and the Info I have been able to collect didn't indicate any resource conflict, but I might be wrong...