Take a look at the fourth post in this forum thread. It's for Vista but I believe it works in W 7 too.
Copy the text between the lines below into notepad & save as a .reg
file. Watch out for line wrap -- [HKEY_CURRENT_USER...\Shell] is all
Windows Registry Editor Version 5.00
Merging the .reg file will set the 'All Items' template for any
folders that don't currently have a view saved with a different
template. You can clear all saved views by deleting the
key BEFORE merging the .reg file. If any folders open with a different
template after clearing the 'Bags' key & merging the .reg file, they
most likely have a template specified via their desktop.ini file.