SupportAssist, taken over file associations

Hi to All.

I have recently updated to the latest version of SupportAssist.

I noticed a couple of days ago that some programs had the blue Dell Support Assist spanner icon inside their folders. Looking inside these folders I found that all the .dat files had the SupportAssist icon instead of whatever icon they should or maybe should have associated with that file in that program. Then I noticed that this was happening right across my whole pc, every .dat file had the Dell SupportAssist icon displayed everywhere. I checked in Default apps under file type associations and there it was the Dell Support Assist icon set as the default app for all .dat files. I've tried setting the default app to another .dat association like a file viewer but then that file viewer icon just replaces the Dell Support Assist icon computer wide. I thought to reset the pc to Microsoft recommended defaults to rest the .dat file association in Settings hopefully to The + icon and the words Choose a Default. I had .dat associated with the file viewer I use and the file viewer icon was displayed, but after resetting all default apps to Microsoft recommended defaults I looked again and found the .dat files Microsoft recommended default must now be the Dell SupportAssist icon which was now reset as the .dat file default app association. 

If I knew how to clear the .dat file association back to the + icon and the words Choose a Default that would do it for me., of course remembering just hitting the reset button for Microsoft recommended defaults doesn't do anything except put the Dell Support Assist icon back as the default .dat icon.

I'm getting ticked off with seeing that white spanner on a bright blue background everywhere I look on my pc! Does anyone know how to do that, please?