When you connect to the internet you can harm your PC. That is a fact. The reason antivirus software and other similar products where created is to protect your PC.
It is not your fault that you got viruses, however you should take the precaution methods to stop this from happening again.
Keep PC Clean: It is important that your PC stays clean if you use the internet. Clean from the 'bad, harmful objects' that are also known as spy ware, adware or viruses.
There are many different types of harmful objects but luckily there exist also cure to keep your PC protected.
A must use Software: The two most important software you must have are an antivirus and an anti adware. There is no need to purchase 30 different kinds of anti spy ware software...
However you must choose two software which will protect your PC. These will work in the background automatically. Some anti adware products also heal spy ware not just adware.
Schedule Maintenance: The software will block spy ware and adware. However you should also use the software when you are offline. You should scan your
PC using both software at least once every three weeks. That will clean any harmful objects. These objects can make a lot of harm to your PC.
Safety Measurements: We already mentioned that you need two software to keep ongoing protection on your PC.
If you download software/movies/images/videos or any other thing from the internet it is recommended that you scan those items. Before opening them right click on them and use your antivirus to scan them.
Go to Control Panel to turn on Firewall. Firewall is also an ongoing protection which is very important.
Once you have your software installed these protect your PC and you get back the freedom you deserve. Remember that prevention is better than cure.