Im working on a buddies computer, its a hp p4 running at 1.6ghz with 512 mb memory. The computer runs extremely slow, it has no viruses and the hard disk is not fragmented. Also, the cd-rw erases any disc put into it, and the dvd rom just slides in and out once you open it. Any idea's about how i can troubleshoot this?

Check Processes in Task Manager to see what's taking all the CPU cycles.

Here's a better Process Explorer from Sysinternals.

Save the needed data and reinstall XP. I suspect you have a virus/trojan even though you think you don't.

+1 watchout for the porn sites.

Isn't that why computers were made?

It is a statistically proven fact, the internet is for porn. And if you analyze the close bond shared by the internet and computers, the answer just jumps out at you. Computers are for porn.

Oh yeah... need to add something positive and relevant to this thread. The thing is obviously possessed, you don't need a tech, you need a priest.

CD drives cannot erase anything. CD are ROM which means read only.

Get adware or spybot and check for spyware

Sarcasm (Of course it runs slow it's an HP P4 with only half a gig of ram) End of Sarcasm.

I say I hope you have what you need to reinstall the os and such, I would just go and do that. Anything that you need to save do so. I recently worked on a neighbors PC an old Walmart Compaq that had 128 different infections, rootkits, a key logger, a bunch of viruses, and trojans.
So I just started from scratch. I also gave them some free ram as they only had 256k.
All the free anti-spyware stuff did not help much in getting rid of the junk that was on the system.
The hidden files and multiple registry entries just made it to time consuming to go the long route.
Blink 4 and Avast are very good anti-virus programs, I recommend them over many of the other free versions.
Ad-aware, spybot and windows defender are great for helping to keep a new system clean.

Clearly your neighbor knows the true purpose of a PC.

You might want to look at which controller you have plugged the devices into, and if there is another chip on the mobo which is better suited. Also I strongly suggest a memory upgrade to 2GB.

EASY
Install and run these three, they are like anti virus and need the latest updates 1st before you scan.
SPY-BOT
From Here http://www.safer-networking.org/en/download/index.html
Microsoft Windows Defender (AntiSpyware)
From Here http://www.microsoft.com/windows/p [...] fault.mspx
Ad-aware 2008 Free
http://lavasoft.com/products/ad_aware_free.php

If you think it could be a virus, or u don't have an up to date antivirus, run AVG FREE
From Here
http://www.download.com/AVG-Anti-V [...] tag=button

All of that Should remove all traces of spyware,

When you defrag, check the report for files that won't defrag, make a copy of them, it will take a while if they are fragmented into serveral pieces, then delete the original and rename the copy. Should work for all files except ones in use, search google or sharaza for moveonb.exe, Handy program to move, copy, delete files that are in use, does this at next system reboot. Careful with anything in the windows directory or subdirectorys though.
Be sure you defrag every drive/partition too.

Lastly Click start, run, then type "msconfig.exe" without quotes.
Click StartUp and you'll see most of the things that start with windows, you can untick any or all, but some programs you may have to leave running in order for them to work, trial and error.
Just reboot, and run msconfig and tick some back on at a time.

And check virual memory settings, I usually set xp to double the ram as a set size virtual memory, eg 256MB ram 512min and max size swap file.
There are other tweaks but i don't have enough time to tell you them.

Hopefully that helps you.

Hope That Helps