There is a
professional version and there is a
free version of Supeantispyware.... Pro SAS has active protection much like an antivirus program...but it is NOT a replacement FOR an antivirus program. If you selected to download the Free Trial that is the Pro version which will not be actively protecting your computer after the trial period is reached. For Malwarebytes, which is another scan and remover program that is very popular, the same is true, the Pro version is a real-time protective one while the Free version just starts and scans and updates when you tell it to.
Here is a page showing the difference between the free and pay-for (Pro) version>>>
http://www.superantispyware.com/download.html
Here are the two downloads shown side by side>>>>>
http://www.superantispyware.com/superantispyware.html
Many of us do use the Free version alongside our antivirus programs. . The free versions do not conflict with anything and we use them just to REMOVE any malware or ad and spyware.... a lot of that type of stuff is not even dealt with by the common antimalware or antivirus suites or programs.
In my experience, there can be some conflicts-- but I am not able to guide or advise you on using an antivirus suite or program along with a Pro version of any of the several antispyware programs or suites. I personally would not recommend doing that for someone who is not really technically experienced, who could recover easily from crashes of their computer, who does not stand to lose a lot of time or money or sleep....when a lockup or some kind of error loop occurs.... not that it always will, but these things are unpredictable since there is so much difference with computers these days.
The main thing to realize is how to keep the system updated, how to avoid ad and spyware, know the symptoms and the common ways it comes in, rather than concentrate on just protecting the computer,. There will I think always be some avenue into the browser or network, the email, or the social networking apps....it would be impossible to do much at all if everything was locked down. You would spend way too much time allowing things to work, to check for updates, to install correctly.....
Here is an article about safety online, about avoiding malware, the scams and bogus apps that you can encounter.....a whole lot of information you should read and heed
How did I get infected?http://www.bleepingcomputer.com/forums/t/2520/how-did-i-get-infected/
Basically, the antivirus program alerts you to unsafe web pages and files, it scans files that you are opening and should be the main protection.... with that said, a few on demand spyware scanners such as Malwarebytes or SAS cannot hurt anything, but I would not run the premium editions until youre more experienced. There are also adware and web exploit blockers that a lot of us use, and some of these are not all that simple to use and would require a little advanced knowledge to use effectively and safely.