Clutch problem

I put in a new clutch kit in my 90 tracker and it worked great for a month.Get in it one day to go to town push in the clutch hit the key and away it goes before i let out on the clutch.It would stop moving if i held the brake and clutch, and not kill the engine a few times .But now it will kill the engine.It feels like the clutch is working? Any Ideas???? Could it be the release bearing or pressure plate? I also tried adjusting the cable. Thanks for any help