Usually Windows will ask which program will be used to open a file when you click on an unknown file types. Notepad becomes of the option available to open the file(s).
To do this trick, you need to change Windows XP registry. First of all what you need to do is to open Windows XP Registry Editor. Click on “Start | Run”, then type Regedit after that just click “OK”. In the Registry Editor, fine the “HKEY_LOCAL_MACHINE | Software | Classes | Unknown | shell” key. Make a new key by clicking on “Edit | New | Key” and named the key with “Open in Notepad”.
The next step is to open the key. Notice on right window of the Registry Editor. There is an entry named “Default”. Open the the entry by double-click on it. At “Value Data ” part, type “Notepad.exe % 1″ (without quotes) then click ” OK”. As the final step, close the Registry Editor and restat your Windows. After your Windows restart, go to Windows desktop, open Windows Explorer. Then find an unknown file type ( for example, a file without any extension), right click on the file. Now, in the open context menu you’ll see one new option in the context menu, named ” Open in Notepad”.
