It would help us help you if you could describe your computing setup. I see that you have entered an "F" drive so some explanation will help here.
Are you saying that whichever directory you choose, ie have you experimented and tried to select all of the directories or drives available to you, the selction does not remain and show up in the sequence module? Eg the standard C drive? A more complete explanation will help.
If you are able to select another directory at least you could continue to use SGP and evaluate it during your trial period. It may not be the drive or directory you want but it won't be a show stopper. This will give time to understand your problem and help find a solution.
There is an announcement post pinned to at the top of the forum that helps new users collect the information needed to help diagnose a problem and then ultimately find a solution, How to Ask for Help.
The manual is a very good resource for help and there are tutorials available on the web made by users. The forum is used by many helpful and knowledgeable folk who are willing to help. The developers are very active on here too: I always bear in mind that they are in a different country to me and so there are naturally time delays in responses. I also remind myself that they also have full-time jobs outside of SGP, families and lives too.