Username and Password required for Network Shares

Ive been having some problems with my WD TV Live box (half my library of movies and tv shows dissppeared and have found no way of getting them back after months of researching)  i decided to roll back my driver before i format my pc.  Ive rolled back and now updated to the latest version but when i click network shares it ask me for a usrname and password which i do not have and never have.

How can i get passed this screen so i can get into my folders?

I tried doing a factory reset but that done nothing to help.

Thanks

If you rolled back your PC Drivers, it probably created a new profile for your Network Settings.

What version of OS is on your PC?