I have a laptop (a Medion from Aldi) that tends to hang quite often - so often, in fact, that several attempts to install Windows XP or Ubuntu on it have all failed.

However, I am able to boot and run Ubuntu as found on the standard Ubuntu 10.10 installation image. I have done this two times thus far.

The first time everything was running smoothly, until at some point the GUI (i.e. X) became unresponsive. The cursor kept moving with the mouse, but menus would no longer show and clicking things no longer produced any response.

So I switched to the consoles (Ctrl-F1, Ctrl-F2, etc., which in this setup automatically run shells. The shells were still responsive, and the cd command would still work, but any command that invoked an executable (e.g. /bin/ls or cd /bin; ./find caused the shell to hang up uninterruptibly. My hypothesis was that all attempts at disk access were hanging up, but I didn't actually try a command like echo /proc/$$ or while read line; do echo $line; done < /var/log/syslog to verify this. Another possibility is that an essential system library is cached in memory and somehow failing to function properly.

The second time I left the system running overnight and it didn't hang itself spontaneously. I'm not sure I have the patience to just twiddle with the running system until the condition reappears, and I'm, not sure what to do once it does.

Clearly we can rule out a software cause. It seems disk access related, but clearly it's not permanent hard disk failure because the system will reboot just fine.

What kind of hardware problem might produce these symptoms? Can it be a memory problem?