Reading http://forums.cnet.com/5208-6142_102-0.html?messageID=3105025 we use other tools plus some miss the advice about "SAFE MODE."
Hope this helps,
I try to run my Avast, Trend Micro, AVG or Norton and they start to scan then just shut down and then fail to run after that. I installed Windows defender and after a short way into the scan it too shut down with an exception error. I ran Hijackthis with the same results. After a short scan it crashes and then fails to run again from the current location. It appears that there was a virus that came in through an email on Yahoo which avast picked up and said it quarentined it. After that everything went haywire. It does not matter what virus or spyware/adware program I run they all exibit the same results. After I do a clean install and run the same thing happens. Also I cannot perform any updates either to the virus or Windows.