The automatic repair didn’t work. I did a system restore to before I installed grimefighter. However the laptop still booted into grimefighter. This time it failed to run because there was no valid license and offered me the reboot.
I did the reboot and windows 8.1 is back.
Thanks to Essexboy for his help with this issue. Avast Support only just replied to my “critical” ticket a few mins ago after 3 days waiting.
My feeling is DO NOT USE this product on windows 8.1 it may kill your machine even if they say it is supported on windows 8.1
Thanks
Sker