Windows 8. Itunes Upgrade Jul 15

Hi all.

Running Win 8 & have just upgraded to new itunes version.

Now when using Get Info to add sort data (album/artist etc) the edited info shows as "Greyed Out", data will not show when using itunes library.

Tracks off a ripped CD & stored on external drive.

How can I restore to previous version of itunes or resolve this issue.

Many thanks.