Trish - 2014-04-29

I've been running a batch file including the following command for months in my Windows 7 64-bit environment for a year and it has worked just fine. All of a sudden, though, it is no longer compressing files. Permissions have not changed. I've installed some Windows updates, but 7za was working fine for a week after that before this problem appeared. I'm using 7-Zip 9.20 and 7za920.

cd\ 7za a -t7z -mx9 -pSOMEPW "C:\Users\USER\Documents\backup.7z" "C:\Users\USER\Documents\backup.bak"

I'd appreciate any insight you may have on how to get this working again. Also, I'm not an expert at this and the compression switch is more than a little confusing to me. I'd like to get the best compression possible. What would the -m switch parameters be for that?

Thank you for your assistance,
Trish