Off with Norton. On with Avast. But what order?

[Keyboard Hound]

I have a computer with the trial version of Norton anti-virus installed and working. I want to remove the Norton and install Avast. I've been looking online and have found several different versions of it. How do I know which is the latest version? I'm new to doing stuff to my own computers and I'm confused.

Do I first download the new and then take off Norton? Or will that cause conflict if I dont' take off Norton first? But if I take off Norton first, won't that open me up to a virus?

As always, thanks for the wonderful help you people always give.

Keyboard Hound

[Collectonian]

Download the new version so you can scan it with Norton. Then, disconnect from the internet while you uninstall Norton and then install the new program. This keeps you as safe as possible from a virus while you transition, while avoiding issues. Particularly on windows, antivirus software uses a specific system hook that can only be used by a single program at a time, so if you try to install the new one while Norton is still installed, at best the install will fail, at worse your computer will go spastic on you because they will fight over that one system hook.

[Matera the Mad]

What she said. Get Avast from its own site, then you'll know it's legit and up to date. It will need to download virus database updates after it's installed, and will also keep an eye out for future program updates.

Then celebrate your freedom from Norton.