Shadow Defender can run your system safely in a virtual environment, or sandbox, called 'Shadow Mode.'
'Shadow Mode' works like other sandbox programs by running everything in a virtual environment with no changes to your operating system. It can prevent all viruses and malware from infecting your regular desktop as well as protecting your privacy. If you have any problems, simply reboot and that will restore your PC back to its original state, like nothing happened.
You can even specify which files and folders are permanently saved to the real environment ensuring that the important ones get retained after a reboot while the less important ones are not.
Some of the advantages of Shadow Defender include a computer safe from malicious activities and unwanted changes - perfect for testing out software and avoiding unwanted changes by shared users.
Sandboxie lets you run programs in an isolated space which will prevent them from making permanent changes to other programs and data on your computer. Sandboxie-Plus also available.
Phoenix OS is an Android-based operating system that you can install on your hard drive or as a bootable DVD or thumb drive. Also available as a executable here.
VMware Player is an easy-to-use application that will offer users the possibility to run any virtual machine on their computer—used by MajorGeeks to test software safely.
VirtualBox is a free virtualizer that extends your existing computer's capabilities so that it can run multiple operating systems in virtual machines at the same time. VirtualBox Extension Pack also available.
Toolwiz Time Freeze is a free instant system protection tool that will protect your system from any unwanted changes and malicious activity in low disk level. Toolwiz also has a complete, all in one suite called Toolwiz Care.