Special character in user name causing problems

Hi
I'm working a friend's PC, and their username / account name on Vista is "Fred & Wilma". Since their account name, including on the hard drive, has the & symbol in it, wsus won't run (it throws out the error message "path may not be more than a 128 characters long and must not contain any of the following characters #$&*@." Is there a work-around for this? Changing the account name is a no-go, as they have a lot of software already installed, and creating a new user account / transferring all the settings etc from the current account is just going to be too hard / too much work.
Any ideas?
Thanks
Peter
I'm working a friend's PC, and their username / account name on Vista is "Fred & Wilma". Since their account name, including on the hard drive, has the & symbol in it, wsus won't run (it throws out the error message "path may not be more than a 128 characters long and must not contain any of the following characters #$&*@." Is there a work-around for this? Changing the account name is a no-go, as they have a lot of software already installed, and creating a new user account / transferring all the settings etc from the current account is just going to be too hard / too much work.
Any ideas?
Thanks
Peter