Fixing the 7z error
I'm led to believe this is a Windows 7 error. But anywho, right click the 7z file in your DFO folder and change the privilege level under the compatibility tab to run as administrator. Do it for the DFO.exe and DFOLauncher.exe too just in case. You may also want to try giving them full control. I've never seen this error again ever since. Give it a try.