I test different products all the time on my production machine, as long as you are capable enough to remove all remnants of the product before moving on to another you should be fine. You can use products such as Revo uninstaller to help with the process. Others here may have a different view on this, but i test them this way as i like to see how they will perform "resource wise" on my real time system. Testing Malware is another story though.