Im planning to build a new system but I want to keep my old hard drive which has anti-virus installed and windows xp installed. I am gong to have 2 hard drive: one is going to a freshly installed windows 7 and one is the old one( windows xp). If I installed an anti-virus in the new hard drive which is windows 7, will it conflicts with the anti-virus installed on windows xp? I will be booting from windows 7.