When you make the modification to the path of the working folder Do-more Designer checks to see if you have write access to that folder. Obviously, you do, that's why everything appears to be OK. However, the actual storage of the pathname you gave it is stored in the Do-more INI file. The file itself is located in c:\Do-more\Designer2_0 and is called DmDesigner2_0.INI. However due to Windows system security, the one you modify is in VirtualStore folder.
Try this instead. Go to Do-more Designer's LunchPad (View --> Launchpad). In the Application window double-click on DmDesigner2_0.ini. This will pull up the "correct file" in your PC's default text editor (Notepad). Scroll down to the [PATHS] heading and manually change the PROJECT PATH. Save the file and exit. Restart Do-more Designer, and then check to see if it worked.
Although you might get an immediate complaint when you attempt to save the file.
If this doesn't work, it may be that your Administrator will have to give you R/W access to where the INI file is stored (i.e. c:\Do-more\Designer2_0) and modify that file.
@franji1 may have something to add or correct...