The AppLocker feature present in Windows 7 allows administrators to specify which users or groups can run particular applications. Unfortunately, AppLocker feature is available in Ultimate and Enterprise editions only.
For those users who are running other editions of Windows 7, here is a small tool that lets you block applications with a password. Windows Application Blocker allows you block specific applications from running.
Download and run Windows Application Blocker (WAB) with admin rights (right-click on the exe file and select run as administrator). On the first run, you will be greeted with Enter Password prompt. Simply click Ok button to start adding applications the Blocked Applications list. One need to type the application executable name to add an application to Blocked Applications list.
When you try to run a blocked application you will see "This operation has been cancelled due to restrictions in effect on this computer. Please contact your system administrator" error. To run a blocked application, run the WAB again and remove the program from Blocked applications list.
Use the Change Password option to assign or change the password. Overall, a nice portable tool to lock applications in Windows 7. You might also like to know how to bypass Windows 7 logon password.