Instructions
Visit the Xbox Live Card website (xboxlc.com).
Enter your Gamertag into the indicated field and select a badge style from the drop-down menu. The image below will display a preview of the Gamercard without your information. Click the "Generate Gamercard" button.
Select and copy the URL labeled "Image URL" beneath your new Gamercard.
Right-click your desktop browser and click "Properties." Select the "Desktop" tab and click "Customize Desktop."
Click the "Web" tab and click "New." Paste the URL of your Gamercard image. Click "OK" to add your Gamertag info to your Windows desktop.