My friend recently got bitdefender, but before he installed it he found his old copy of Kaspersky and installed that instead. He gave me his registration key of bitdefender and I went to install it from the net, but it says that it could conflict with my AVG and asks me to remove it. Before I risk a noob-ish mistake, I thought i'd ask. (Also, I used to have an account on here, but I forgot my information, so I started a new one today.)

The AVG I have is only the 30 day trial and it has 4 days left. Should I remove it and use Bitdefender or re-install the AVG for another 30 days?

What do the more informed use for virus/spyware/adware protection?