Hey, Im donig this for a friend.
I inserted the XP cd and the setup popped up. But it wont let me click on Install windows XP (i wanted to select upgrade). So I created a new partition with 10 GB of space (by shrinking the one that has vista running). I then rebooted the comp and then started the windows XP setup and selected that partition. I dont know why but for some reason I selected to format the partition, again, although i formatted it before the comp was off.
Anyways, then it copied the files and when it was going to restart it gave me this when loading - "An error was found in the drive" or something like that. Just that message, white font on black screen in the top left corner.
Since its not mine but my friends I really want to fix it as fast as possible.
Thanks!

What exactly are you trying to do? Do you want Vista and Xp on the same disk or just XP?

Prety much just XP.
Im using SP2 disk.
Its currently formatting at his house, like complete format.

Yeah that's the best to do then. If it doesn't work download a gparted live cd and do a low level format then try the reload.

This is due to vista partitioning the second one as a logical instead of priamry partition you can have both on one hard drive i think but you need them to both be logical.

I believe you installer CD (for XP) offers the option to delete partitions (when you boot off it). What you need to do is delete both partitions, and then create a new one from all that RAW unpartitioned space. Then, format it to the filesystem of your choice and install XP! Best of luck!