My pc was recently afflicted with the winpc defender trojan. I ran a full mcafee scan and the annoying pop up's stopped. the winpc defender icon in my vista tool bar also seemed to be gone. but now my pc will not startup in normal mode, it will go as far as the user log in selection screen for a couple of seconds then the screen turns all blue with no text and the pc automatically restarts. when i log on in safe mode i can go on line but my search engine is still hyjacked as if the trojan is still present. I've downloaded the malwarebytes program but it will not run! I'm pretty sure I've followed the instrustions correctly but when i click on the icon on my desktop i get an hourglass symbol for about a second then nothing happens. I've run subsequant mcafee scans in safe mode and two issues arise: ntoskrnl-hook, and c:\windows\temp\ual918c.tmp. the scan says it removes these items but I've run the scan several times and they reappear each time. good god this is making me mad lol. im not the most pc savy person and my patience is almost gone. please someone help, I can't afford a new pc right now. thanks.
You have a rootkit. These are programs that are designed to bypass normal security and hide programs, files, and registry entries as well as protect those entries from normal user or system access.
You need to start your computer using a Boot CD. You can use the Windows CD to start a recovery console, but this requires some use of the command line and the knowledge of what files and services are bad.
Optionally, if you can burn a CD on another working computer, you can use the Boot CD I created that includes access to a graphical user interface and AntiVirus scan/clean functionality.