First, I'm suprised the NAV scanner does not detect this one.
My machine is Windows Visa Home Premium.
Second, I've got the same symptoms, first taking me to a web page,
http://piscanner2.info/25/24-050wLzIzLGBzL==
Which tries to fake you out with a screen that looks like a windows firewall screen. clicking on the screen, or sometimes doing nothing instantiates a popup/application, deceptively trying to get you to do a download. X-ing may work, or clicking on the buttons seems hazardous, so I usually just kill the browser.
The file paths listed above do not exist on my machine, nor do the files stated. This must be a trojan that automatically renames itself and moves itself around. I can't find it either by visual inspection.
No particular rhyme or reason as to when it starts. For the record, I use Firefox most of the time.