Tsunami Gaming

my dad's computer has this thing where sometimes the computer will be on, and doing absolutely nothing.. but the cpu usage will shoot up and down. ex: 20%, 79%, 57%, 48%, 99%, 38%, 3%.. and it'll do that seemingly randomly.. I've done disk cleanup/defrag/spyware/virus checks and even stand by mode & turning it off altogether thinking it may just need to cool down... restarting it will make it go away, but it'll eventually start doing it again.. and it just slows down the already slow comp.. anyone know the reason why it's doing this??

I don't know much about comps so if you need answers to any questions about stuff like memory size or whatever.. I cant give that cuz I don't even know where to look to find out =(

Is the hard disk "thrashing" as well?

Can you hear it spinning up.. is the red light in the front flickering, etc.

yes.. that was what made me check with ctrl+alt+delete.. it made all the noise like it's really busy.. while it just sits there

I am guessing your probably using XP or older, so you won't have Windows Defender to edit startup items, but you can use Spybot S&D (http://www.spybot.info) to do the same thing. In Spybot S&D use the Advanced mode (gives extra menu options) and locate the 'Startup Items' tab in the menubar on the left. In here check what's being loaded at startup and disable anything you don't actually NEED to be running, good examples to disable include qttask, jusched and realsched, which are all background programs that do nothing except nag you to update stuff and waste resources.

There is an arrow on the right hand side of this screen that if you click on it it shows an expanded info area that tells you more about the currently selected item, so you can decide if you want to disable it. Be careful to note that some items have multiple definitions, including both genuine and spyware versions, so read through the whole description before choosing to disable something. If your not sure about some items you can screenshot the page and post it here, and myself or someone else will see what you can safely get rid of.

Not only should it help the CPU usage, it will also reduce memory usage and most likely make the system boot up faster.

Could just be simply a hard drive failing. Might want to find out exactly what the issue is as quickly as possible and consider having a backup plan in case your hard drive breaks.

I was having that problem when I set the (page file? where it uses the HDD as memory) too high. It was constantly using that and as a result continually working the hard drive, which isnt good.