iTunes doesn't recognize devices after installing version 11.3

I am running Windows 8.1 and downloaded the iTunes update (11.3) this morning. iTunes no longer recognizes any of my devices so I'm not able to sync. I have an iPhone5 and an iPad2. I've tried connecting the devices with a spare cable just to rule that out and it made no difference. Any ideas how to fix this problem? I saw on the forums that others are experiencing similar problems but I was not able to find a solution.

Thank you!