Protection probably OK - but absolute PC brake

I have a precaution Once downloaded and installed the 30-day trial. A lucky!
I would claim that I am familiar with some good Internet Security's.
F-Secure I tested for someone else, because the one who is in Unitymedia and there is offered with this package.
Of course is important to the protection of the PC / Notebook and the effects of working with the PC.
I have set all the settings as far as the suite after my findings themselves.
From the beginning, I immediately fell to the slowness of the laptop, (is no longer the latest).
For example, start the PC and Firefox call were an ordeal - a shortcoming, which falls through with me now!
So down with the installed F-Secure and my proven ESET and I'm happy again.
How to come up with as a security software cope inexperienced PC users. I do not think and probably only with continuous frustration.
With such a security would and I do not want to deal with for days. Either it never works right from the start or.