try this way log in on www.dell.com go to "Your Account" -> "Find My Products and Services" ->  on drop down menu select "By Service Tag" -> enter the service tags in the box or select a csv o txt file to import a list of service tags... after that you import all the service tags, go to "My Products List" and enjoy it!
Hi, I have a large number of service tags. Is there an easy way to enter multiple service tags to check the warranty status on all of my hardware? Thanks,Paul
Checking multiple service tags