time machine permission help

I have a mac Mini
Max OS X ver,10.6.8

I performed a reinstall and unfortunately did not keep a last back up of my files on the mac mini hard drive,
but what i do have is a time machine backup hard drive,
BUT
when i enter the time machine hard drive i have the following error what can i do to resolve this issues so i can get to my files?

The folder “Desktop” can’t be opened because you don’t have permission to see its contents.

Under system Preferences in Accounnts, under My account i see my new account with my new name, but under this i also see other Accounts and i can see my old account with my old account name listted as admin, how can i change my new account name to my old account name ? maybe this will resolve the problem?



when i goto the permissions of the folder they are greyed out!!! not allowing me to edit or change the permissions