Netbook randomly shutting down or restarting

Question

Machine: Asus EEE 1201N netbook / Windows 7 32bit

At first I thought it was my video drivers/codecs because it would only happen while playing a video (streaming, off hdd, whichever. and at random points - sometimes 5 mins into the video, sometimes 20 mins.). So I updated my video drivers/codecs but it didn't change much. Then it started doing it randomly (it could happen as I type this). Sometimes I get a BSOD with "driver_irql_not_less_or_equal" and "dumping physical memory etc etc", other times not.

Questions:

1. Does this sound like a hardware fault or a software fault?
2. Are there any windows logs I can check to try diagnose the problem?
3. Until I find the solution, are the constant restarts/shut downs hurting my netbook?
4. What diagnostic tools can I run to see where faults might be?
5. Could it be the USB data dongle (from my mobile service provider) that's causing the problem? I don't remember experiencing the problem before installing this thing, and I've heard lots of complaints about the firmware being buggy etc.

edit: regarding the shutting down OR restarting bit, i just realised that when it gives the bsod (with driver_irql_not_less_or_equal etc), then it restarts. other times the screen just goes black and the machine switches off.

Answer 1

To determine whether the problem is with software or hardware, use Unetbootin to create a bootable Linux distro on a USB drive, and boot your netbook into Linux. If you can use Linux for hours without a reboot but Windows reboots and shuts down without obvious reason, the problem is software.