What should I do about my computer?

My CPU usage was up too 100% and now it slowed down but not to normal. What do you guys think is wrong with my computer could it be my hardware going or just some dust built up on one of the cables from the motherboard is causing the problems. Do you guys think I should repair it or just use it till it breaks and get a new machine. Its only a HP 8665 with a 30 GB harddrive and the processor is 605 MHz and what really sucks is the ram is only 128 Mb. So what do you guys think I should do please let me know. If there are any computer wizards that could help out a wizard. Also someone told me to reseat the heat sink how do I do that and where would I find it. Normally I'm great with computers but I'll be damn if this one hasn't got me.

Thank you to anyone who answers.

What should I do about my computer?hijack this

Yes, check for spy ware, try spybot it has worked best for me. Also, stopping processes from starting will help, some. How often do you reboot your system? You may be getting what is called memory leaks. If you keep your system on all the time, try rebooting to 'reset' the ram.

Another thing you can try is defragmenting your hard drive. If you download and delete a lot of stuff from your system, this may also be a source of slowdown.

Looking at your system specs, you are fairly outdated by todays standards, and if you are running XP, you will not get much better at all, period.