Why does my computer keep freezing up?

This happens at least once per day (but sometimes several).

It freezes up, and my only option is to unplug. Ctrl+Alt+Delete doesn't work, and neither does the power button.

I haven't done anything I can think of which would cause this: I haven't installed any new software. I haven't downloaded anything in quite some time. I've kept up on running anti-virus / anti-spyware programs. I've kept up on Windows updates. And so on.... I feel like pulling my hair out.

Dunno if this info will help, but here's goes...

Windows Vista Home Premium

Manufacturer: Hewlett-Packard Company

Model: a6019h

Processor: Intel(R) Pentium(R) 4 CPU 3.20GHz

Memory: 1015 MB

System Type: 32-bit Operating System

Any advice?

Why does my computer keep freezing up?security

These freezes can, many times, be related to bad or intermittent hardware, or simply mismatched hardware. Mismatched hardware is common, even some of the large computer manufactures do insufficient analyses and testing when they select the components that make up their systems. Many components that make up a computer just don't play well together. Some modems just don't work well with specific video cards. Some sound cards are incompatible with certain main boards. The list goes on. Many manufactures only look at the cost of a given part, not its compatibility, thus they can often produce unstable computer systems. please check for any new hardware that u mightve installed recently.