Restoring files from a backup created in Win 7 to after Win 8 upgrade

I need a piece of advice about restoring files.
I used to have regular backups on network drive when used Win 7 in past. I just did a clean install of win 8. I can see backup folders date wise in the network drive. Each folder shows a sub folder with name Catalogs, Backup files 1, Backup files 2 and Backup files 3. These folders contain the whole system data including documents. How can I retrieve documents from these in Win 8. I will appreciate help.

Finally I could recover my files using 7 Zip from the backup folders created in windows 7. I did not try but methods also exist to extract files from image files in both win 7 and 8.