If XP, post in the XP forum.

As to loss, we only lose what we don't backup. Also, if this machine has suffered some virus/other damage then it's anyone's guess if the files will survive.

Remember that XP and today's "programs" are designed to thwart backup and restore. No need to complain to me about this. If you wipe the OS, then "programs" are designed to fail on restore.

Are you sure you need to do this?

Bob