The registry can be modified easily to make way for a lot of tweaking. Blocking access to an application is one of those great things. No, as usual, I’m not going to use any third-part app (as they can be dangerous). Lets do some registry hacking by ourselves!!
1] Click Start –> Run… or hit WinKey+R on your keyboard to open the Run… dialog box.
2] Navigate to HKEY_CURRENT_USER/Software …
3] Right-click on any empty space in the right pane, and go to New –> DWORD Value.
4] Name the newly created DWORD Value as disallowrun. Press Enter to confirm the renaming.
5] Double-click disallowrun (which you just created) and make sure the Value data is 1 and the Base is Hexadecimal. Click OK when you’re done.
6] Again, right-click on any empty space in the right-pane, and select New –> String Value
7] Name the new String Value anything. I named it notepad, as I want to block the Notepad application. Hit Enter after renaming the file.
8] Double-click the String Value which you just created, and enter the exe name of the file you want to block. It is notepad.exe in this case. To find out the exe name, open Task Manager (by typing taskmgr in Run), and identify the exe name of the application you’re running. Type it into the Value data and click OK.
9] Close the Registry Editor, and restart your computer. You will find that the application is blocked.
Comment if it worked, or didn’t!