Windows 7 needs to know what use name you'd like to use and how you'd like your computer to be identified on your local network.
In the Type a user name (for example, John): text box, enter your name. You can enter a single name, your first and last name, or any other identifiable text you like. This is the name you'll be identified by in Windows 7.
Note: You're more than welcome to use the same user name that you used in your old operating system installation.
In the Type a computer name: text box, enter the name you'd like your computer to have when being viewed by other computers on your network.
Note: If it makes sense in your specific situation, I recommend using the same computer name you used in the operating system installation you've deleted as part of this clean install, especially if any other computers on your network connect to resources on your PC.
Otherwise, a good computer name might be Office-PC, Windows-7-Test-PC, Bob-Dell, etc. You get the idea. Anything identifiable that makes sense to you will work.
Click Next when you're done entering both the user name and computer name.
Note: Planning on having more than one user on your computer? Don't worry - you can set up more users inside Windows 7 later.