To be honest - from a person who used to work for a software house
None of them are any good

As soon as you buy them the bug writers have written a lot more bugs and hackers are writing more cr*p too, and unless these software companies are:-
A Aware of the problem
B Work in the language that the bug is in
C Have the workforce to write a patch or fix to stop it within 4 hours
D Have an automatic update that has good filters and works properly on your disk
I'm sure I have missed something else too -
I had Norton for 10 years. The only think I hate about that bloody company is that when you want rid of it, unless you understand hidden files and where to get all norton files deleted,
besides the normal un-install routine -
it is still sitting on your disk and interfering with any new software that you install -
they make it difficult so that you will give in and go back to upgrading your Norton
- crafty, scheming little *******s'
I now use Kaspersky - and that is turning out to be useless too - used to filter all spam and now lets everything through - even standard viagra which should be blocked from all angles.
So - Hope the free one works -
but the best bet by far is to go out and buy a plug in second storage unit that will take all your user files and photographs and settings -
and
BACK UP EVERYTHING at least
once a week - that way you only risk losing a weeks work.
I know I sound like a help line person - had to do that for a while too - Is the computer switched on, is the plug in the wall, have you switched................. thank god for alternative living

Julie x