[DESPAIR] My PC suddenly and randomly crashes or reboots

[Katapom]

Hello.

In the last months, in which I used to run Arch Linux and now LMDE, my PC randomly crashes (with Arch it returned me a kernel panic, it stops working plain and simple with LMDE), or reboots.
In case of reboot, it often does not reboot at all - I have to turn it off and restart it manually.
I have noticed serious slowdowns in managing Flash animations or other graphics-demanding apps.
What can I do to understand what is going wrong in my PC?

[itsme4401]

Smels like a RAM-problem.
To make shure: run memtest for a longer time.

[Katapom]

Smels like a RAM-problem.
To make shure: run memtest for a longer time.

I've ran memtest for nearly 3 hours, made about 10 rounds of all tests. No error founds.
I've tried removing some addons: the TV card, the memory card reader, the ATI HD4650 (the built-in video processor is an Intel 946GZ), the network card (the gig one, not the built-in 10/100 one), but it still looks to not work good - it did not hang yet, but when I moved the case a little the PC rebooted. Flash animations are still very slow, and 3D games flick a lot.

How ill is my computer patient?

[äxl]

What kernel do you use?

Code: Select all

uname -r

Could you switch to an older one?