1. This will help you reset the admin password. ($45!!! No way! Here is a program that does the same thing for FREE!)
2. No, you cannot restrict users from dropping files of a specific type of file into a folder. (again I hate to disagree but of course you can!)
To restrict users from saving specific file types you can either use group policy via active directory, group policy locally, registry edits or impose a antivirus restriction prohibiting specific file types.
It all really depends on your network setup.