I got a free one-year license for BitDefender a while ago. It seems it was responsible for the terrible performance on one of my computers; a bit of searching turns up a lot of bitter complaints about its CPU usage. There is some indication that by default it checks hourly for definition updates.
Since I disabled automatic updates and Web traffic monitoring (and pretty much everything else except the on-demand scanning), I have noted a considerable performance improvement that I cannot readily attribute to other factors.
ratfink wrote:On XP, it gave me sporadic "windows is not genuine" errors. Microsoft's own fix [to do with data.dat permissions] did not work. But because the problem is sporadic, it's a few hours before I find out. I guess it's to do with how often it contacts their server or something.
In searching, I have found at least two ways to get around installing WGA with MSE: you can either download an older version that can install without needing WGA, and then let it update itself; or you can the special installer someone cooked up which hooks into the MSE installation app. The latter is said to work on XP only.