Hi i want to be able to edit MTEXT in my DWG with the help of notepad. This way i could just print the drawing in DWG-trueveiwer. When i try this, AutoCad thinks there is something wrong with the file and wont open it. Any thoughts?

I think it is a dumb idea.  Notepad is a generic text editor that is used to create, open and read plain text files.  If the file contains special formatting or is not plain text it cannot be read by Notepad.

DWG files are binary encoded, with lots of checksums. You cannot edit them with Notepad. On the other hand, their text version - DXF - can be edited quite conveniently for this purpose.