Leodis wrote:
I know I'll never want to pay for an anti-virus as long as the freebie is doing the job adequately
You get what you pay for. You might want to keep that in mind when you think the freeware/trial version is adequately doing it's job.
What your using is either a freeware version or a timed trial version. The whole point behind it is to give you an example of what the product can do so you will buy the retail version.
Aside from reverse engineering the program (which is illegal) I doubt their's any way to turn off the advertisement. However, if you do reverse engineer it and remove the ad, you probably won't be able to sync up to the update server which means no more updated definitions.