I've seen this when a computer has some bad media files, such as .mp4 or .flv, and the thumbnails option is attempt to display them constantly, and failing.. It causes .dllhost.exe to run constantly, as well as conhost.exe.
Have you got any dodgy media files?
Hope this helps.
I am constantly losing focus to Conhost.exe and DLLhost.exe. I am using Process Explorer to tell what is taking focus, and both of these programs will steal focus and then crash seconds later, only to repeat the process.
I've had the problem intermittently (about one every hour or 2) for a few months, but just recently, I will lose focus constantly, about ever 10-15 seconds until a restart.
I can clear up the problem for a an hour of so by restarting my computer, but it occurs most often when playing a game, fullscreen.
I've tried uninstalling/reinstalling programs that I've recently added, but nothing works. I'm going insane and would appreciate anyone help.