Sowercrowd, the backup utility gets the installation path for WOFF from the windows registry so It shouldn't be wrong. It would greatly help me if you were to use "windows explorer" to display the folders path to WOFF and then do a screen capture of the windows explorer display and PM it to me.
I am sure we can get the problem resolved so you can use the backup tool. Your's would be the first time I couldn't resolve the issue, so I really want to get to the bottom of the problem.

Robert_Wiggins, the path is "E:\OBD\Wings over Flanders Fields_UE\OBDWW1 Over Flanders Fields", while win 7 is installed on "C:" Long time ago, when i had WOFF2 installed on drive c: backuputility was working fine. If i now type in "e" or "E" in the DOS cli it tells me "WOFF is not installed on this drive.Try again." If i type in "E:" i get "Drive E: does not exist. Try running again." Maybe it's a registry issue ?

...forgot to confirm that "MyWOFFSetupFiles" is created in "Windows (C:)".

Sowercrowd, your directory structure is non standard, and certainly not the default, and this may be the problem. I also suspect that the registry entries for WOFF do not match the actual location you identified. Did you manually move it at some point.
That said, I wonder if you would kindly download the backup program again from Sandbagger's web site, on a hunch that you may possibly have an older version of the program.

The normal structure would be:
"driveletter:\OBDSoftware\WOFF\OBDWW1 Over Flanders Fields\"

"driveletter" above would in your case be "E".

I look forward to hearing from you.

Best Regards

....sorry for late response, RL kept me busy. You are right, i copied the whole WOFF folder from C: to E: ,i must have changed the default path, though i can't remember. However, after the recent crash i did a complete reinstall, carefully following OBD instructions which included registry cleaning via toolbox. So what can i do ? Changing the directory structure back to standard wouldn't be a good idea, i presume ? Right now im saving the essential files every 5 missions.

Correct me if I am wrong, but it seems you are saying that when you did a complete re-install you changed the directory destination from the "default" location, to the one you identified earlier to me in this thread, is that correct? If so, then the registry entries would match the current location and everything would be fine.
Since you manually copied the whole WOFF folder from C: to E:, I suspect the OBD instructions for reinstall would not be aware of the files that were manually moved and they would need to be deleted manually by you. Failure to do so may have some negative effects.

I can only suggest that if you do a full install again, let WOFF set the default directory structure on the "E" drive and then try my backup program again. It should work fine. I look forward to your response.

Best Regards

...i don't dare messing around with the registry , since my pc skills are very limited. I'll adjust the path with the next full reinstall. Thanks for your help !