Backup

Hi...
Tried this question earlier, but didn't get any response.
Please let me know, if the question is unclear....
I've made a full backup of my C: drive, using Vista's backup feature.
I've saved the backup on a local disc, called my E- drive.
Then I have formatted the C-drive, and reinstalled Vista.
I wanted to restore some of the files from the backup, Documents
etc. but now Vista is telling me that there is no backup on the selected
drive.
Even though I can see the backup in Explorer. It's around 90 Gb...
I have changed from Vista Ultimate to Vista Business, but that
shouldn't make a difference, or what ?
Any other programs that can help me getting access to the
backup ?

Regards, Kim