ComboFix will not run

I am trying to run combofix but it will not fully load. I get the "Preparing to run message" and then that window closes. I disabled my antivirus (Avast) but got the same results. I went as far to uninstall Avast just be sure. Any ideas or suggestions? I've used combofix on other computers with no problems.

 

Hi jfields,

Please skip Combofix and try running SuperAntiSpyware and the other scans in the READ & RUN ME FIRST. Attach the logs you're able to get.

Thanks.
abri