Are you running XP? That path only exists on Vista, and not XP, because for security reasons apps cannot write to "Program Files" on Vista. That path holds the output of the optimising compiler before the final exe is copied to AppPath. It looks like Dbasic.exe thinks you are on Vista. As a temporary fix, until Erel replies, you could try creating that path and see if it works. It won't do any harm.
Then you should have a "C:\ProgramData" folder. Vista aware apps write to it instead of writing to Program Files and so can run as normal users. Non Vista aware apps that need to write to their "Program Files" folders need to be run as Administrators. I thought it was created on Vista installation but I am not 100% sure - lots of things may break without it
Ok just delete the file and B4PPC will recreate it and all is well.
Now my next problem is CS0246: The type or namespace name 'CEnhancedButton' could not be found (are you missing a using directive or an assembly reference?)
Look in "Program Files\Anywhere Software\Basic4ppc Desktop\Tzor". Do you have a "CEnhancedButton.cs" file in there? If not there should be one and that is the problem otherwise I don't know what might be wrong.