corrupt boot + master boot sectors

[Apokalipse]

just this morning my computer wouldn't boot, it would get to the XP startup screen and then for about 1/10 of a second it would show the 'blue screen of death' and I saw some hexadecimal values. I put in the XP CD and went to the recovery console, I didn't know how to work it before because I never used it but I figured out what the commands do with Help, I rebuilt the boot and master boot sectors and now it boots fine.
what could have corrupted the boot and master boot sectors?
- and I know I didn't have any viruses

 

[Press_F1]

whats the message on that blue screen?
How many HDD are you using? Do you have a multi-boot system before?
changing you MBS is a very risky procedure.. so better cheak these question first before you do some changes.
were happy that your PC work just fine now.

success!

 

[Apokalipse]

I have 1 hard drive in 1 partition (NTFS), and XP home in 2 installations.
I did a chkdsk in the recovery console and it told me there were a few errors it fixed, and that the boot + master boot sectors were corrupt and needed repairing. since I could not use it without rebuilding them, I felt it was my only option.
apparently there was a bit of a power line problem in our area, could this mean there wasn't enough power, and the computer misprocessing the boot and master boot sectors?

 

[Apokalipse]

and I had to change my boot.ini afterwards to this:

[boot loader]
timeout=20
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Home"
multi(0)disk(0)rdisk(0)partition(1)\BACKUP="Backup Windows XP"

 

[paintballer]

I had a similar problem, I just ended up backing up some files from safe mode and reformatting (i was gonna do it soon anyway) What happened with me though was that I went to log on the blue screen came up and then it restarted.