1. Use the latest version of Bandicam
2. Start Bandicam before the recording target program
3. Turn off UAC or run the recording target program as administrator.
4. If you still can't record, send an email at email@example.com
with the following information
1) Can you record with "Rectangle on a screen" capture mode of Bandicam?
2) Do you use Windows XP or Vista/7?
3) What are you trying to record? (YouTube videos? or Minecraft games?)