Is Cyberdefender a good anti virus program?

Installing multiple antivirus programs actually makes each program less effective and can cause other problems too. You should NEVER have more than one antivirus program install.

Cyberdefender is a good program; however no program is perfect. In fact the truth is that they are all very far from perfect and they have a hard time keeping up with the constant changes in malware. Which program is the best is purely subjective and can change several times a month as new version and new updates become available.

The free programs are all quite good and provide more than adequate protection. Most problems still occur on properly protected PCs due to poor surfing habits and/or lack of security education on the part of the people using the PCs.

I don't understand your statement about having problems with free software. Neither Norton nor ESET are free.

You should read this How to Protect yourself from malware! It works quite well. Is it perfect? No. But again it is only as good as the people using the PC. If you don't follow the guidelines, you will have problems sooner or later. I never have malware problems and do more surfing than most people; but if I gave a 15 yr old full access to my PC with administrator priviledges, I'm sure they would have it infected in less than an hour. After a few days of access, the PC would have dozens of problems.