|If you have a password to log on to the computer use that password. If there is more that one account on the computer any password with administrative privileges should work.|
If you do not then try to create one, sometimes this works and sometimes it does not but you have to be able to boot into safe mode.
Shut the computer down for thirty seconds> restart the computer and tap F8 as it is booting until the option screen appears then choose safe mode. Select the administrative account.
Next go to start> control panel> user accounts> select your account> add a password to it or reset the password. Restart the computer.
Run the cd again and use the new password.