[davidbrownds]

Us this tool it will allow to to change the time to 1.7 hours. But every 24 hours Exchange will reset the time back to the default and you will need to use this tool again. When you run it you can set the time to 100 minutes, than go into the Lock settings and change your time from 20 minutes to 1.7 hours.

Unzip the file and copy the EXE to your Phone than just run it on your phone.