If this is the Windows Operating System asking because you are trying to install Firefox then that is something you should have set up and know. IIRC some versions of windows may allow you to use the system without actually setting up a password, and in some circumstances may start up in Windows Safe Mode using the Administrator account without s password being input. Here is information regarding Windows XP (although you seem to be on vista) * http://support.microsoft.com/kb/321305 * this articlemay be worth looking at http://4sysops.com/archives/three-ways-to-reset-a-windows-vista-admin-password/