Some details please.
You have Windows XP and a Technician repatriated it. He left a spare copy of "My Documents" on a spare drive.
IMHO that is not a problem.
The problem is when you do not have a backup.
If you have limited disk space you should:
- Remove unwanted Videos from the drive.
- Uninstall large programs you never use.
- Use DVDs to backup the most important documents.
- Get a larger hard drive.
Removing a large directory that is part a backup is not a good idea.
Only remove things you do not need in the backup.