Per one of our users:

You have to turn Data Execution Prevention off prior to installing the software. Right-click on My Computer and choose Properties. Or, simply open up System properties from inside the Control Panel. Choose the Advanced tab and under "Performance" choose Settings. Now choose the Data Execution Prevention tab and select the option for "Turn on DEP for essential Windows programs and services only." Reboot the machine, install OOTP 9, and it should be good to go. I believe that following the installation you can actually restore the original DEP option and the program will continue to work fine.

It's been running fine so I decided to try to re-enable DEP for all programs. And, I've found that OOTP will work fine if you add two exceptions. "runservice.exe" in the windows root directory and "ootp9.exe" in the OOTP install directory.