1. 1. Use the Start menu’s Run option to launch Regedit.
2. 2. Navigate to "HKEY_CLASSES_ROOT\*\shell". If it doesn't already exist, then create it.
3. 3. Under the "Shell" key, create a new key called "Open" and change value of the string "(Default)" to "Open with Notepad" (without the quotation marks).
4. 4. Create another key under the "Notepad" key called "Command."
5. 5. You'll see a string value named Default when you highlight the "Command" key. Double-click Default and enter "notepad.exe %1". Click OK.

Note: The new full path is: HKEY_CLASSES_ROOT\*\shell\Open\Command