upgrade dell inspiron 15r 5521 i3 3227 u cpu 1.9 ghz from win 8 to win 8.1 with no luck

I am running 64 bit with 6gb ram and plenty of hd space but can't get it to upgrade successfully to windows 8.1.  Gets to the end of the update and then fails with error 0xd0000225.  have had multiple ms experts attempt to help with no luck.  Can i revert to windows 7 and then go to windows 8.1?  I don't know what else to try.  I bought the laptop from dell in 2013 with windows 8 installed