I’ve had Grime Fighter for a while now and it definitely performs the job that it says it will. I one thing that I really do not like about it is the fact that when I want to run it I have to hard wire it to my router to get it to work. Normally my computer runs through the WIFI and I don’t even think about it. The way that Grime Fighter initiates the scan prior to windows booting up my D-Link never goes through the start up sequence and so if I’m not hardwired to the router my PC has no internet connection which the Grime Fighter must have to run. My Router is a couple of rooms down and it’s a real pain to move my tower whenever I want to run Grime Fighter. I don’t like the way that is set up. If anyone know of any workarounds without having to get a 50 Ft ethernet cable I’m all ears, but i’m not too hopeful.
Can’t help since I’ve not experienced any problems connecting through WiFi when running Grime Fighter. 
I have alerted a moderator who will hopefully pass this on to Avast.
Hi
If I’m understanding correctly
To add, it’s mentioned many times in Grimefighter forum https://forum.avast.com/index.php?board=63.0
that some WIFI adapters are not supported by Grimefighter and requesting a Refund could be appropriate.
I’m not sure this is the OP’s issue however Davidek (Avast team) has stated this in many topics in Grimefighter forum
Also it has been stated by Davidek, that this issue and others will be addressed in the next GF update apparently this Spring (Feb-March)
Added info> Some fixes applied in latest version: https://forum.avast.com/index.php?topic=165749.0
I purchased grimefighter in nov 2014 and it has never shown Up on my panel ,so that I can install the licence .
I have the latest 2015 install can any one let me know why it does not show in the scan menu please?
Regards peter Oh the desktop is hardwired to the internet.