well then it mite be viruses and/or spyware, you could also try red/loading the emulator, or it mite even be tha rom ur playing...
another tihng, check how much ram is being used up by the emulator before it freezes, and if possible after it freezes because it's possible that the ram may still be the problem
ctrl+alt+del > processes tab > find the emulator and under the Mem usage column it will tell you
Edit: I know your fairly new here but try to avoid double-posting lol ;D