When attempting to rename or delete a user profile in Windows XP, you may encounter an error message, "Error: Cannot Rename File In Use" or "Error: Cannot Delete File In Use".
Resolution:
Make sure you are not attempting to rename or delete the profile for the account you are logged in with.
Right Click My Computer
click Manage
expand System Tools
expand Local Users And Groups
inspect the contents of the Administrators group
If the user account you are trying to rename or delete is listed in the Administrators group, you will have to remove it from the Administrators group
Then reboot
you will now be able to delete or rename the user profile