IE7 came out in 2006. Probably a bit late to be checking it? I'd suggest checking it in IE9 instead. IE9 does contain an emulator that supposedly shows how older browsers will render the page, but it's somewhat unreliable.

if you were running a modern OS I'd suggest using XP Mode as a sort of sandbox emulator... er, but you aren't.

To be honest I wouldn't worry about the 2.3% of people who might still be using IE6. Unless you're using a lot of dynamic functions (HTML5, etc) I would not expect significant problems.