I saw this yesterday from an users with XP. Peaked at 100%.. We are using the latest Eset Endpoint Antivirus enterprise. I disabled (saw others report this as early as 2007).. but didn't work. Only fix was getting it to restart. Monitoring now. One solution from Eset pointed to WSUS 3.0 which we use but stated the fix was released in 2007. Other, updating to later subscription releases, which are behind on where we are at..