iPad 1 update from 5.1.1 to 7.1 How can I update iPad 1 from iOS 5.1.1 to iOS 7.1?

I tried checking for updates but I get a message "your software is up to date".
You can't install iOS 7 (or even iOS 6) on an iPad 1.



Source: http://www.apple.com/ios/features/

The last version of iOS capable of being installed on an iPad 1 is iOS 5.1.1 and since this is the version that you are currently on there are no updates available.