Hi !

When you use notepad, instead of double clicking on the icon on your desktop ( if you have one there ), right click on the same icon and select "start as an administrator" ( should be close to that cause I use a french version of Win 7 ).

After editing  a few files using this startup procedure, you can try starting it by double clicking the icon.  I don'T know why but notepad ( or Win  7 stops bothering you ).

Just to make sure I don't waste time making a big edit and ending up not being able to save it, I always type a few characters first then try to save.  The rest is history...