If you want to avoid a lot of headaches, do the following:
#1. Regularly back-up your data. The more back-ups you do, the better.
#2. Avoid running your computer as admin. Set up a user account on the system that does not have admin rights.
#3. Have a single decent AV program. Win7 & Win10 have their own built-in AV software, but having something like McAfee is necessary since they will update their software much more frequently. Note, McAfee tends to be more resource-demanding compared to other AV software. Eset(if I remember the name correctly) is suppose to be much lighter and works just as good.
#4. Use system restore software that protects your Master Boot File. Basically, you reboot to restore your system to its original configuration. There are a number of different kinds out there. For example, I use Deep Freeze(Standard) by Faronics.
#5. Despite all of this, there are some things that will still get through, for example, root kits can get through. Most people do not encounter them unless they are going to websites that are high risk, such as porn, pirate sites, etc.
Consider vectors. Do you have a lot of different contacts, such as friends, that you communicate with regularly via email? If you do, the ignorance of your friends regarding security could put you at increased risk as well as place you on a target list for spam emails.
With the way things are going today, it would be a lot simpler to just set up a virtual machine and do all online stuff from it and store any work that needs to be saved to a separate drive. Not even a root kit would persist and would simply get wiped once the virtual machine is stopped and restarted.