Usually we open an unknown file type with "Notepad" so it would be nice to add "Edit with Notepad" option in right click menu of every file type.
Here we go :
* Open Run Dialog (Press Window Key + R).
* Type regedit & press enter
* The Registry Editor Opens Up.
* In Registry Editor goto "HKEY_CLASSES_ROOT\*\shell" .
* Type : 'Edit With Notepad' (without quotes) as key name .
* Now Click On 'Edit with Notepad' key and in right hand pane right click : New - String Value.
* Type Value Name : Icon
* Now Double Click 'Icon' string value and type : "notepad.exe,0" as value data.
* Right Click On 'Edit With Notepad' Key .
* Choose New - key.
* Type Key Name - command.
* In right side pane of command key double click 'Default' and type : notepad.exe "%1" (With Quotes).
* Click OK.
* Now Right Click Any file & u have edit with notepad option for it.
For simpler option download the registry file to do all this for you....