ME1 game briefly pauses during every mouse and keyboard click

Mass effect 2 and 3 run fine, however 1 has an issue where the game will freeze (audio cuts out, video freezes) everytime i click or press a button. 

This is obviously unplayable. 

I have tried the same things listed here https://answers.ea.com/t5/Mass-Effect-Legendary-Edition/Issues-with-ME1-FPS-Stuttering-PC/td-p/10340093

I have reinstalled the game, updated graphics drivers, deleted the iga64.dll, etc.

Very frustrating, have started trying different hardware, seeing if there is anything wrong. 

please advise.