Hello to everyone.

I just got a new computer with windows vista and was wondering if i was to use limwire to search and download music and video would it make my computer slower or put un wanted software on my computer? I've heard things about limewire adding software like spyware etc; to people computers. I'm looking to purchase limewire pro. What anti virus software should i download to protect myself before i download the lw program?

comp spec:
windows vista home premium 32bit
250 harddrive
1gig ram
amd athlon dual core processor 4600

my system has firewall on it already so what do i have to do to disable it and enable it when i finish with limewire?

All help would be greatly appreciated...