Issues Running SH4-v.1.4 on Windows 8.1

I'm new to the site so if this has been addressed in the past, please point me to the thread(s). I used to run SH4-v.1.4 on a windows XP(sp3) desktop. I now have a Dell running Windows 8.1 with 8 gigs RAM and installed v.1.4 to run SH4. I have tried to run the game in ADMIN but no help. My first issue is that it won't run fullscreen even though I did follow the directions in a thread here (config file set to run fullscreen). My second issue is when I run a saved mission, it gets to a certain point and the screen locks yet the audio continues to run. Sometimes I can open Task Manager then close it and the game resumes, sometimes it doesn't. I tried to run the training sim and it didn't cause an issue. It seems to only happen in one of the saved missions (actually the only saved mission) I am trying to complete. What can I check? Carry on......