Information about product warranty status will be displayed. Step 2: Here, enter Service Tag or Express service code in Enter a Service Tag box and click Submit button. You can easily check the warranty status of your computer if you still have Service Tag or Express service code (usually pasted on the back of the device) with just a few simple steps via online service. To know the warranty status of Dell devices such as desktops, laptops, buyers can check on the website, Support Assist software or via SMS PBX.