Hello Torgek,
You should turn off the PC, it shouldn't ruin anything on your PC. Once you boot back into Windows, please try to run GrimeFighter again. It should take up to 2 hours or so to run, definitely not 70. We did release a patch last week to fix this issue so hopefully it will work for you now.
If it persists to run for more than 2-3 hours, then please open a support ticket with your Avast5.ini file. You can find this by going to Program Data, Avast Software, then Avast. Please include that file in your ticket and also mail to me so I can follow up directly.
Thank,s
Davidek