Here is some great information from the TechRepublic on how to change a computer name.
Rename a computer
When you set up Windows 10 on a new PC as a clean install, Windows automatically creates a random computer name for you using the word DESKTOP, followed by a hyphen and seven random letters and numbers.
If you never use a local network, you can safely ignore that name. But if you share files with other computers, it helps to use descriptive names that make it clear which device you're connecting to.
To change the computer name in Windows 10, Click on Windows Icon go to Settings > System > About. The current computer name is near the top of that page, with a large rename this PC button below it. Click that button and enter a descriptive name using any combination of letters, numbers, and hyphens. (no special characters or spaces allowed.) The maximum length is 15 characters.Then click next to finish the renaming process and then restart your PC.
In Windows 7, the process is similar, but it uses the Computer Name tab on the System Properties dialog box instead. For a shortcut, click Start and then type systempropertiescomputername (with no spaces) in the search box. Click the search result, click Change to enter a new name, and then restart.
