This computer is acting up. It's crashing frequently to the point that it doesn't respond at all. Alt-Ctrl-Backspace does nothing, Alt-Ctrl-Del does nothing, and the NumLock does nothing. It always happens when my friend is running runescape, but that's the only real load that's on the computer, so it might even be heat problems. I recently put some new thermal paste in there all nice and good but it hasn't helped much. There's 256MB in the system too.

We're running the latest Java, installed via RPM. Mozilla is version 1.4.2. And we're running RH9. Up2date also updated everything right after installing the OS. Any ideas? Anything helps, thanks!

Does it do the same thing running another OS? Have you tried booting a Knoppix cdrom? There are two very likely causes. One, your updates have been too aggressive. More likely though, there is a hardware (heat?) problem, especially when you can't exit the GUI. As an alternative, I'd suggest trying alt-ctrl-F1 (or another function key up to F6). Most modern desktop managers try to restart when killed, so ctrl-alt-backspace simply leads you in a loop.

Check your Xconfig files, there might be an answer there as well.

If your keyboard isn't responding at all, then it's a pretty hard crash. If you can't ctrl alt backspace, then you can't change to a virtual terminal either.
If the machine is on a network, try to ssh to it and do
killall X
that might drop you back to the login, or to command line. That's the way to avoid a reboot.

There may be a few factors contributing to the crashing --- buggy video drivers -- bad ram -- overheating -- or a bug in the program. It's easiest to eliminate overheating, so chase that down first. There's more than thermal paste involved with cooling. Make sure all power connections are good and your fans are spinning free of obstructions (cables can sometimes shift over time and prevent fans from moving).

Run memtest86 overnight and see what it comes up with. Also try formatting your swap partition and checking for bad sectors on that part of the hard disc. Memory is especially sensitive; swap space is no exception since it's treated as RAM as well.

Try changing video drivers. If you're using Nvidia or ATI proprietary, try changing to the generic "nv" or "radeon" open source kernel drivers.

See if you can duplicate the problem reliably.

When all venues are eliminated, send a bug report to the software vendor.

--Shade