When you setup your computer then you need to choose user account name for your computer. But you can change user account name on Windows 7. Follow few steps by step guide to changing username Windows 7.
Changing User Name Windows 7
1. Click up to Start button and click up to user account image.
2. Click Change user account name text to change windows 7 user account name.
3. Type a new name for Windows 7 into New account name box.
Click Change Name button to save this new name on your Windows 7 user account.
4. You will see your recently added username on Windows 7 user account.