I Tunes and Windows 8.1

Just moved to Windows 8.1 from 7- what a bad decision I Tunes worked easily and perfectly under 7

I have Windows Media Player installed. I have a large library of Operatic arias under composer, performer etc. I can open them with difficulty but it then informs me it can not find the selected item and wants a file name- try various names , none suceed.

Can you help.

Robert