For testing other IE versions, I use the free
IETester. It’s ridiculously buggy (the Back button, for instance, doesn’t work at all) but it will do the job for rendering your pages in Internet
Destroyer Explorer 6. It also does IE7 and 8, in case you only have 9 installed.
Alternatively, if you have an extra XP license lying around, you could easily install an XP virtual machine using the free
VirtualBox. Then you would have the real thing.
Another possibility is to use
Microsoft Expression Web Super Preview, which is also free. Personally I don’t recommend this as it’s totally static and won’t let you test Javascript or even click links.
Hope this helps.