you do really need a good all round package
Virus protection is a good start ... but not the whole story
I like Kaspersky internet security ... I'm sure the others will roll out their fave tired suggestions also (I know I just did ;-)
whichever one you go for - the security suite is probably your best bet ... plug and play ... just install and forget... and no compatibility issues.
the techies tend to prefer to use separates ... and that's good ... if you know what you're doing ... if not play safe
I've just installed a copy on a chum's machine today
(they buried the cat today as well!)
it cost �15.00
http://www.google.co.uk/products?q=%22kaspersk y+internet+security%22+oem&btnG=Search+Product s&hl=en
I know... I know ... oem ... but it's a new PC ... I'm sure they MEANT to pre install it.
At the moment it's still all the magazines' favourite ...
I use it on all my machines ... and install it regularly on others.