Sandboxie

Sandboxie is a tool that separates programs and prevents unwanted changes from happening. For example, you could run your browser in isolation mode and download malware and your primary OS will not be affected. This is assuming that there is an exploit for Sandboxie and the malware doesn't take advantage of this.

I do not recommend purposely downloading malware and testing the boundaries. This is a layer in defense that will help increase your security for when you are visiting unknown websites or running unknown applications. Sophos has recently made the application free. If you are running Windows, I recommend checking it out. Visit the link here to visit the site https://www.sandboxie.com/.

Other Options

Windows 10 is introducing a sandbox mode that is essentially a virtual machine running on your machine. It will allow you to open suspicious files and visit suspicious websites without much concern.

The other option is to run a full virtual machine using Hyper-V, Virtual Box or a VMWare product to separate your isolation. This is the method that I current use. I typically follow the PAW method for systems.