It is "administrator" (without the double quotes). You can get
a list of all existing accounts like so:
- Click Start / Run / cmd {OK}
- Type this command:
net user
It's the old, well-known problem. When you get a
new car, you always make sure you have at least
two sets of keys, for obvious reasons. When you
get a new PC, you make sure you have at least two
admin accounts, for equally obvious reasons.