By this point most business workstation computers are setup as domain members. If changes need to be made you log on as a domain user with administrative privileges and make system changes. If you need to logon locally for some reason you type the account name in the HOSTNAME\USERNAME format. DOMAIN\USERNAME will then get you back in as a domain user. Typically, through my experience anyhow, PC names are printed on a label and stuck to the box itself or are readily apparent in some way. One network I found myself supporting used the service tags as part of the computer name. What a pain; particularly since the drop down domain/hostname “logon to” box is a thing of the past. The quicker way to log in locally? Simply type “.\” (without the quotes) and then the local username. For instance .\administrator. You can log on without having to muddle your way through a long, cryptic hostname.
I hope you new XP to Windows 7 converts out there find this useful!