Opps! I got a case of Vista

Hello all,
I have a question that may sound dumb but here goes.
If you had XP installed on a computer and did not have the disk, then using a down loaded version of Vista put that on you computer, could you go back to XP with out buying a new disk and doing a reinstall? Also if you could would you loose any data?
For the record I am posting this "q" for a friend who's daughter likes to mess with things. She is having all kinds of problems(I think it is from a bootleg copy of Vista, she thinks Vista is bootleg)
I told her to just start from scratch.
Thank you

 

Buiy a legal version of XP and install it to a blank drive. All data will be lost.

 

YES!!,
More or less this was to prove my point although I had herd that there was a way to "revert" back to a prior OS with out loosing data, but I think you need the disk
Thank you for replying

 

Just so everyone knows "But if you used a torrent copy of Vista " I did not download, steal or any other non legal thing I really am posting this for an embarrassed co-worker
DaveA:
So what about backing up all important files and the doing the uninstall? most of the files were made on XP Would she be able to access the now that vista is gone?

 

Any files she wants to keep can certainly be copied to a CD or flash drive before the process begins. But I wouldn't count at all on files being saved during the process, even if all goes well.