Whatever security software you have installed on your system, they won’t protect your system becoming a mess if you keep installing and later removing software from your machine. The problem is, all sorts of files end up all over your PC, filetype configuration can get confused, your Registry ends up with irrelevant entries and startup items are left on your machine and it takes longer to boot.

The ideal scenario would be a virtual manager. Microsoft Virtual PC 2007 is a free virtual manager, but you’ll need to install another copy of Windows on top of your existing OS. That means you’ll require another license and some lowly editions of Vista do not like virtualisation at all. You’ll then run an OS on top of an OS and use this virtual machine for your testing. Not always ideal.

Returnil Virtual System is a virtual manager with a different. Instead of running a virtual OS, it will mimic your current system partition and load this in to memory. You can then install and play with software you’ve downloaded, then come out of this virtual system without leaving a single trace on your installed operating system. Your Registry will not be affected at all. Should you then wish to install properly, you can do this safely, knowing it won’t affect your Windows installation.