I got a virus too, I tried all the above stuff but it doesn't work. I tried restoring the defaults, the fix from Microsoft, deleting the registry keys I haven't got, running gpedit.msc which I haven't got too, running a specific program, I'm going to give
up...! How many steps and I still haven't got it fixed, it's strange, the tray icon doesn't seem to be a very complex tool...!
EDIT I also tried a procedure on MS site to restore the Action Center but some requested files were unavailable, maybe the virus damaged my PC a lot. It works now, but I can't see the notifications which are very useful. It's very uncomfortable to have to reinstall
everything rather than restoring a single service. Moreover, I was able to restore the Windows Update service by a third-party utility, whereas Fix It didn't work.