To have Notepad as an option in the Send-To options will greatly simplify the process of opening the text file with an unknown file extension. The following are the steps to take.
1. Right-click desktop, choose "New --> Shortcut".
2. Type the location of the item - "notepad" - (that's all, no need to give path).
3. Next --> type name for shortcut - "Edit with Notepad".
4. Click Finish.
5. Now right-click this shortcut on the desktop, and choose properties.
6. Confirm that the "target" and "start in" fields are using variables - "%windir%\system32\notepad.exe".
7. Now, browse to "%UserProfile%\SendTo" in explorer (which means "C:\Documents and Settings\User_Name\SendTo\" folder).
8. And copy the "Edit with Notepad.lnk" file which you already created, to that folder.
9. Now you can right-click on ANY file-type and be offered an option to open with notepad from the SendTo sub-menu.
