As a result of your screen is locked, or any screensaver is running, taking an IE screenshot returns a black image.
You will need to turn off your screensaver and configure windows to ne'er lock itself once not in use. To turn off your screensaver:
Then modify your screensaver settings. Make sure you have unchecked "On resume, display logon screen".
While you're in the control panel it's probably worth checking the power options and making sure the machine isn't going to sleep or powering down after a set period of time as well.
You will also want to use VNC or remote assist to access the GUI. If you RDP in it will lock the screen for the local user who is currently logged in and again it will lock the screen when you disconnect.
Finally, don't use the 64-bit IE driver, you should be using the 32Bit one. Hardly anyone runs IE Driver’s 64Bit version (even if they need a 64Bit capable machine)