HELP!!!

I seemed to have lost all my photo from the my pictures file on my internal backup hard drive.

I've been backing up all my pictures for a number of years onto a spare hard drive in my desktop pc tower without any issues, but I went to look for a picture today on the backup hd only to find that all my pictures have gone.

If I put in the backup hd search box the words "my pictures" it show me my 26,242 pictures but when I click to open any of them it I get the error code 0x8000000a.

Please help as a lot of these are of my daughter growing up.

I'm running windows 7 64-bit

Many Thanks

Andy