Further to ss44's comment above, I agree with him that a little recap may be helpful
1) You have two odd files on your computer (a) AVGINSTALLEDAPPX.EXE and (b) YSIGNU~1.EXE
You are not alone, there are several posts on different forums (Techsupport and bleepingcomputer as examples) with regard to these.....but as yet there is no clear answer as to what they do or if they are legit or nasty.
Other security progs such as malwarebytes/superantispyware are not picking these up as threats...nor are the main "on-line" scanners.
The consensus of opinion amongst the security specialists on these sites is that the files are probably legit and part of the new p2p scanner in the latest versions of AVG...but not even the well known and respected experts in the field can get a confirmation one way or the other from Grisoft/AVG.........so doubts that they may be bad still exist.
2) You are still getting the pop-up that freezes your PC ?
In this respect, the report you have to the effect "You don’t have AVG installed on this computer" is interesting........it may be, as suggested by ss44, that your AVG has expired ( but in that case I would expect a report to the effect that it has expired, not that it does not exist)...........but it may well be simply that your installation of AVG has been corrupted, either by a nasty or some other means.
If that is the case, an uninstall/reinstall of AVG may cure the problem.
How did you originally install AVG.........was it preinstalled when you bought the PC or did you install from a disc or did you install from a file downloaded from AVG. If the latter, do you still have that downloaded file stored on you computer ?
3) Let's not think or worry about re-installing Windows just yet........that is an extreme measure, and the final measure to take only when all else has failed.
4) I am with razpaq when he questions the need for a paid-for av prog. The free ones are every bit as good at detecting and eliminating nasties. The benefits to the domestic user of the paid versions are more frequent definitions updates ( in the case of my Avast, that is every hour rather than every two hours ) and technical help....and despite the fact that you have paid AVG for this help you are not getting very much.
Don't fret and worry, chrissie, between us all we will beat this thing...
edit to add..........one crumb of comfort, chrissie, the two odd files in question are to be seen only on PCs with AVG installed.........which does suggest that they are connected with AVG and are not general infections.
