Bitdefender is an awesome program!! It is affordable and has great features like laptop mode and game mode. Has several scanning options (Deep system scan, full system scan and quick scan.) With the ability to purchase licenses for several computers and years at a time, it is one of the most reasonable programs out there on the market. I highly recommend it for all and it is proven to work on Vista x64 (I have it on 2 computers with x64).
It has won the following awards:
