Old time machine backup prayed out, why?
Hi Not very technically minded. I did a total erase of my HDD i was not worried because i have a 2TB WD time machine backup. When i try to go to that to restore certain files i have problems as described. When entered Time Machine i got the star wars effect but i could only go back to the start of the latest install. I then entered TM via system preferences and it states the oldest backup date but when i select disk its not there. If i then go into options my other external HD's are showing as is my old TM, however only the TM is greyed out.
Why and how to do access this? Any help would be gratefully appreciated as this is where all my music and films are stores.
iMac, OS X Yosemite (10.10.1), iMac (27-inch, Late 2012), 2.9 GHz I