Why Can T I See My Files In My External Hard Disk Drives After An Virus Infection

So, I did a system restore to a week earlier and my PC recovered but the files on my 2 of external hard drives (which were connected to my PC the time when the virus hit) have ‘disappeared’. I’m on Win 7.

However, I can see my files (greyed out) and I am able to retrieved them in another older PC (windows XP).

I think it has something to do with the virus (I’ve since scanned my PC and hard disks files with many scanners and removed all possible hackers/trojan.exe files)

So now, how do I get both of my external hard disks to work normally again on my Win 7 PC (I don’t want to do transfers of all my files as they’re about 1TB)?