Slow comp with Weird lines

ok so i boot up my comp and when i get to the Windows XP home edition logo the loading bar near the bottom will stop for a few seconds and do it for about 5-8 times. Everything is slow when i do something so like when i open my IE7. Also when im playing GW i get this weird horizontal line across my screen usually its the upper half.

Sry no pics of it. But i can have my char just stand there and it will have those solid lines show up then disappear. I ran a video card benchtest and expected to get the lines especially on the massive overdraw but it never happened.

My CPU is P-4 3.2 GHz, video card is Radeon X850 (have most recent driver [4/8/08]), RAM 512 MB.

Ive already tried CHKDSK and didnt really get anything out of that. Im totally clean on the virus side just some few cookies. Did a defrag like 3 weeks ago.

Need some help with this plz

That's a very recent driver. Did you have this problem before you installed the driver? If not, roll it back

Incidentally, the latest Radeon drivers are dated 4/16/08 -not sure if there's any difference Catalyst 8.4

Go to Start, Run, and enter the following code:
Next, we'll run CCleaner, then do CCleaner's Issues section.

Here are some instructions on how to do this:
http://wiki.lunarsoft.net/wiki/PC_Maintenance#CCleaner
http://wiki.lunarsoft.net/wiki/PC_Ma...Cleaner#Issues

Make backups when prompted!

After running this (you'll need to run the Issues scan more than once) go ahead and restart your computer.

Now we'll make use of RegCompact.NET. It will compact your registry (defragging it in a way) to help optimize things. It will require a restart as well.

After you do so, you should notice some performance increase. You may want to run defrag again. You can use AusLogics Disk Defrag or use the built-in Windows defrag.

Hope this helps, and if you have any questions feel free to ask.

Any other ideas before i start on Tarun's idea?

Check your case and fans for dust build-up.