What's your opinion (based on your experience with) Sandbox apps to isolate Windows programs?

I try out a lot of software and this tends to clog up Windows. So I thought (rather than breaking this bad habit) that I'd start using some Sandbox software to isolate software I'm trying out.

Goal: to be able to completely remove an app so that (to Windows) it's as if it were never installed.

I see that there are a variety of them.

Sandboxie (freeware) - Sandboxie is one of the most talked about and widely used free applications in this group. It's not so much designed as a "total desktop" solution, but as a way to isolate certain programs that pose a risk - like web browsers. Podcast on it: http://www.grc.com/securitynow.htm#55

Trustware Bufferzone Similar to Sandboxie, Bufferzone is more about isolating threats from the internet than completely locking down your system. It's designed to isolate apps like your web browser, email, and peer-to-peer programs. Downloaded files inherit Bufferzone's protection, so if you install something that was downloaded from a protected app, it becomes protected as well.

I'd just use virtual machines.

As Ward mentioned, a virtual machine would be ideal for your purposes. You can snapshot the disk before installing a piece of software, then roll it back to the point before you installed it, and it's completely gone.

However if you're determined to go with the app virtualisation route, look at Altiris SVS. It's an enterprise-grade product but a non-commercial version was released for free a few years ago. It does pretty much what you describe and isolates both the application and any data that application writes (ANY data).