My problem occurred when I booted my Windows 7 laptop yesterday (HP), and saw after logging in that my desktop background had reset itself to the factory default. Also, the shortcuts present on the desktop were also different from before, and some files (documents) I had placed on the desktop were not there. The Quick Launch bar was also empty except for Internet Explorer and Windows Media Player. When I ran some programs (Firefox, VLC media player) I got some screens saying 'this program is not your default program for ... ' as if I ran them for the first time.
When opening Windows Explorer, I also found the quick access 'Libraries' were all empty. I checked C:/Users/Myname and found all my files there as usual (thankfully), but something is clearly out of the ordinary. It's almost as if I have logged into a different account on the same computer, which is not the case as there is just one (with Admin rights).
Thinking this may have been the results of a virus/malware, I have run a full system scan with AVG and MalwareBytes. AVG removed a few things tagged as 'tracking cookies' and MalwareBytes removed 2 undesirable registry entries tagged 'non-malware'.
Can anyone tell me what may have happened to my computer? And how I can reverse it?
(I can check if it is done automatically, but I do not make system restoration points regularly. Which may be unwise, but I do not use this laptop very often.)
Thank you for any advice!