I had bought the previous version of Bit Defender which I was particularly pleased (efficient, good value, convenient for a family). I just installed the 2011 version on a computer in 2 years under Vista no problem; everything works. There is even improvements over the previous version of the tools and the level of optimization. For cons, I also installed on two older computers (4 and 5 years, under XP); they are strongly slowed down; I may have to uninstall (with regret) this antivirus from these two computers.
