Shoutbox

Hi everyone, just wondering if you could give me some help with this..

The other day i decided it was about time I formatted and did a fresh install of my XP Pro as there was alot of unwanted programs etc and i felt it could do with a cleanup as its been a long time since the last one.
I then backed up everything i needed to and proceeded to format.
The computer had 2 partitions created by its previous owner that i had just got used to. I wanted to get rid of them and combine to one.
I read that i had to boot from my windows cd so i went to do that and found that my xp pro disk would not boot from disk (Err. No operating system found). Tihs was a pain and i thought i was stuffed. However i remembered a brand new copy still in the packet we had of XP Home including SP2. So i decided i would have to settle for that.
To cut it short all went smooth with formatting and reinstallation of important programs but within a day it was experiencing completely random freezes. and i am talking about freezes so bad that ctrl alt del doesnt even respond and the only thing i could do was hold power button.
This started getting annoying and i figured i couldnt put up with this and knew it would probably happen to me during some important school assignment or something. I hadnt finished reinstalling everything so i decided something must of gone wrong and came to the conclusion it would be easier and less stressful to start over and format and fresh install xp home again.
I did all this fine and was back to a fresh copy and empty harddrive. All of a sudden i began experiencing the lockup freezes again. I knew it wasnt a bad program i had installed as all i had at this stage was the operating system and MS Office 2000.
So now i have no idea what to do. I have installed a few crucial programs for now to get me by until i work out what i can do.

Sorry this is so long but if anyone can help me out with this problem it would be great as this is getting fairly frustrating and i need to get back to my assignments (which was one of the reasons i wanted to format so my needed programs would run smoother).

Thanks for your help