I'm running X Window System Version 6.8.2
Release Date: 9 February 2005
X Protocol Version 11, Revision 0, Release 6.8.2
Build Operating System: Linux 2.4.21-27.0.2.ELsmp i686 [ELF]
Current Operating System: 2.6.11-1.1369_FC4smp #1 SMP Thu Jun 2
23:08:39 EDT 2005 i686
Build Date: 13 May 2005
Build Host: decompose.build.redhat.com

I get freezes just about every 15 - 20 minutes while in a shell, trying to access Yahoomail, opening windows, random stuff. Is
there anyway I can set back my system to a previous state when it was more stable?

Is there a way to kill a process or do a killall in linux?

How can I check what's causing the freezes and why my system is so unstable?

Thanks

Usually that type of stability problem isn't caused by software, but rather by hardware. Have you added any new hardware to the system recently (exceeding the power supply capacity)? Have you checked for dust buildup, or failed fans on the case, power supply or CPU? Have you checked your drive temperature to see if it's running over the manufacturer's limit?

I like macemoneta's advice on the hardware side.

Thought 1: I'm currently a Windows user, playing with Linux. Windows can be temperamental with power management from time to time, usually when it comes to sleep or hibernate mode, which I've seen kill the computer in a timed basis like you describe.

Thought 2: Have you tried reinitializing xorg with Ctrl-Alt-Backspace?