1. A few weeks ago my house got extremely dusty. I had to clean out my PC fan filter. At the same time I tried to scrape some dust off the GPU and spun the fan round a few times. Could this cause my GPU fan to stop working? and should my GPU fan be running all the time because it is not? This is because my computer seems to be crashing often and the screen locks up but I can still here something working and the screen changes to different shades of black (flickers). This make me think that it is something to do with the GPU. I opened the case and felt the GPU and it burn't my fingers! (My GPU is a Nvidia Geforce 7900GS)

2. A few weeks ago I downloaded an illegal version of UltimateDefrag (i know illegal software sucks and I've learn't my lesson). I was made so it would fun off a USB but I just ran it from My Documents. It seemed to work well speeding up my computer except in Test Drive Unlimited (PC game) where it was laggy. I decided to run windows defrag and this is what it looked like.
http://i133.photobucket.com/albums/q54/Dav...m1/untitled.jpg

After many defraggings all that changed was the arrangement of the fragmented files until it no longer changed at all. And it looked like this.
http://i133.photobucket.com/albums/q54/Dav.../untitled42.jpg

Please help me and if you need anymore info please ask.

1) Your CPU fan should be spinning at all times as should the fans on the graphic card(s). You are experiencing blackouts because the video card is getting too hot.

2) Different defragmenters work in different ways as to how they arrange files on the hard drive. You'll usually find that using anything other than the Windows Defragmenter will cause obscure results to appear in that program when you use it again. Quite how you get it out of this I can't say unless anybody knows better.

Just to add to NJs comments, you have way too many files on that drive to be able to successfully defrag it. You need at least 15% free space, more will make it work better. Looks like you need to invest in another drive and move some things to it.

in reply if you look at the top of the defrag box it says 65% free space. thanks for the help anyway.

last night my GPU fan did come on for a minute but then went off again and a few minutes later it crashed.

You must investigate why that graphic card fan is no longer spinning - is it catching on something? Does it have proper power and is it plugged in properly? You will continue to have these problems as long as your graphics card fan is not working. Your card is getting too hot and that is what is causing the crashes.

The fans in a computer are the cheapest and most unreliable parts. The best thing is to buy a new fan. If you can't find one you can carefully open the stickers that cover the shaft bearings and apply a drop of light oil. Usually the sticker cannot be used again so you have to cut a small piece of sticky tape to cover the ends. It is also possible that dust collected between the center of the fan and the stationary parts of the assembly. Blow the dast and apply a drop of oil.

In short, buy a new fan.

thanks for all the help.

my pc went into a repair shop and they said it was the fan that had broken. it was a dell. i'm getting a new gpu and the defrag problem is still a bit baffling!

Read through this entire thread again. You could have saved yourself some money because that repair shop just told you what Neil and The Skeptic already had. The fan on the GPU can be replaced along with a new heatsink if you would like. This would also save you quite a bit of money if the GPU was not permantly damaged from the heat.

thanks for that but i'm not that technical. I'm a 16 year old boy whos parents went mad with him coz his pc went wrong. I'm not going to chance fixing it myself. Thanks for all the help guys.

thanks for that but i'm not that technical. I'm a 16 year old boy whos parents went mad with him coz his pc went wrong. I'm not going to chance fixing it myself. Thanks for all the help guys.

Our pleasure. honestly.