Hi all. I run a dual boot Win2k and Linux machine. Everything has been running fine for years, until yesterday. When in Win2k, the machine would do a hard reset every five minutes or so. It was quite unsettling, to say the least. It was impossible to work, so I popped open the case to see if there was anything obvious wrong (I suspected a dead cpu fan), but there wasn't. The machine seemed fine internally - no loose cables that I could see, and the cpu fan was definitely turning.

So I booted into Linux, and everything seemed fine. I worked for a few hours. Before I went to bed I started a few silly scripts that would keep the cpu working at 100% all night.

When I checked the machine in the morning, it was frozen, and the hard drive led was on. I have never had this happen to me under Linux, so it was VERY unsettling. I wasn't able to do anything about it, so I rebooted the machine.

I'm thinking it might be a hardware problem, and cooling is still my first candidate. The system is an AMD k6-II 400, not overclocked, and, like I said, has worked flawlessly for about a year. I upgraded to 400Meg RAM about 4 months ago, and have not experienced problems until now.

Any ideas would be most appreciated.

First, make sure the power supply fan is running. If not, replace the entire unit.
Then, check that the CPU, RAM, and all cards are fully seated.
Look for any dust build-up on the fans, in the vents, inside the computer, etc.
Check for other things that can cause overheating(computer next to a heat source, vents blocked, computer in an enclosed space).

If the above are ok, then it could be due to a failing power supply, some bad RAM, or even a quirky CPU.
Install just one stick of RAM. If the same thing happens, replace it with another.
If swapping the RAM does not work, then you will have to swap out the PS and/or the CPU.

Thanks, ski.

I ran some long scripts on the Linux side, and although it seemed more stable, I still managed to get *top* to segfault, which I took as a sure indication that there was a motherboard level problem, probably ram. I opened the box, and vacuumed it out thoroughly, including the fans and the power supply. Then I removed the ram, vacuumed their sockets, and put them back, all in different slots. I powered up, and ran memtest86 all night. By morning it had done 7 complete cycles through its test suite with no errors. I booted into Windoze, and that's where I am now. It seems ok, but I'll see after the day, since I'm running some memory intensive stuff right now.

BTW, the memtest www.memtest86.com (http://www.memtest86.com) is a great, free utility.

Thanks again for your advice. Cheers.

You're welcome, wombat.
Thanks for posting back, and hope the system stays stabilized.