Update: Tip on Installing Mango 7720
"8th In the directory "NoDoToRC" the file "ISV_Provisioning_Live.exe" run as admin (right click, ...) ... 19th In the directory "c: RCToRTM" and change (if still connected phone) the file "ISVTo7720.bat" run as admin (see above)."
If you are attempting to install Mango build 7720 on your phone and get an errors on step 8 while trying to install "NoDoToRC" the file "ISV_Provisioning_Live.exe," try it without right clicking and running as administrator. Simply double click it and let it run. The same goes for step 19 (ISVTo7720.bat).