|Well I sure stuck my foot in my mouth on that one.|
You can open 'my computer', then 'local disk (C:)', then 'documents and settings' to see what user folders are there. I'm not sure but I think if you change a user name the folder name doesn't change so that may not help if an administrator account has been changed. However there could be more than one account showing there that may have administrative privileges that you can log on to.
Normally you'd have the administrator user and then a separate user account with administrative priviileges that you'd work from so maybe the original administrator account is still untouched.
So try logging onto the administrator account. There's some basic info here:
on how to do that and how to recognize an account with privileges.
I don't have the option on mine to switch to the administrator account and have to use F8 when booting to access the menu and choose 'safe mode'. Then the option to boot to administrator shows up.
You're not really green until you're soylent green.