HP Quad core machine with 4 Gbytes DDR 667 RAM, running 32-bit Win7 Professional. GT9500 video card and a poor-quality power supply.
The primary problem is that when I run Windows Updates, and am presented with a choice to "automatically" download and install the presented updates "Important" and "Optional", if I simply press the "Install Updates" button, everything seems to work normally. Some updates download and install, but apparantly some do not, because if I press either or the updates (Important, or Optional), Windows Updates freezes, Explorer.exe crashes, restarts, all the running programs appear just like they were before the restart and Windows Updates is closed.
This will repeat infinitely. Every time I click either "Important" or "Optional", Explorer restarts.
I run every diagnostic I can think of.
Ran sfc /scannow and it seems to close normally indicating that the files are all legit, but I have not actually seen the log to confirm this. I've run numerous rootkit detection utilities, Farbar, Hijack this, etc... Autoruns and cannot find any kind of entry point. Ran Hitman Pro, Eset online scanner, Housecall online scanner and other than a few minor "PUP"s, no significant malware has been found.
This whole thing started when I tried to install Visual Studio Community Edition 2013 (the free one, found online), and it refused to install properly despite numerous repairs and reinstalls. A standalone copy of Visual Studio Express (ISO mounted and ran locally) has the exact same failures. Key registry entries showing the path the the .exe file(s) are missing. Other than that, I seem to have no other symptoms. No pop-ups, redirects, unusually long delays, CPU usage or memory spikes, nothing that indicates infection. Which makes me wonder if it is some kind of keylogger, doing surveillance (recording) only? Not sure.
I can't imagine why a malware would interfere with a Visual Studio. Windows Updates makes more sense. My guess is that there is a security fix that would patch the hole that the malware wants to prevent from installing, but why interfere with Visual Studio?
So that's it. Windows Update and something to do with Visual Basic. Any help appreciated and thanks in advance.