Running IE6 and IE7b together

Three methods. Which is best?

[dhiggerdhigger]

I have found three sources documenting different ways of being able to test a website on both IE6 and IE7b on the same OS. Which is best?

Method 1: Install IE7b, then standalone IE6 from evolt.org. I'm not sure I want to install a beta which messes with my operating system.

Method 2: Don't install IE7b (uncompress the exe installer instead), and run IE7b through a DOS script, which cleans up IE7b's tracks when IE7b is closed down. The IE6 installation is untouched. (Search for "IE7 Standalone Launch Script" in Google to find this method, by Jon Galloway.)

Method 3: Again, don't install IE7b, but delete certain files and create a text file with which IE7b will run happily. No mention of undoing any registry changes, but maybe there are none with this method? (Search for "Using IE6 and IE7 together" in Google to find this method, on tech-recipes.com by risherz.)

Which is best?

[dhiggerdhigger]

I should say for readers even less informed than I am (before others who might know for sure may contribute), that I'm leaning toward Method 2 (Jon Galloway's) because my OS remains untouched and it's the only method which seems informed with regard to registry changes (undoing them when IE7b is closed down).