Hi, keithfay. I'm newbie to Pelles C, but have you closed your application before recompile it? When my application is still running, and I change the source code and try to rebuild/execute, I have this error ("POLINK: fatal error: Отказано в доступе."). With another IDE/compiler we had something like this situation because of antivirus software (sometimes it blocked creation of the .exe file).