Well I’ve just upgraded to IE7 on my new development laptop and it’s very refreshingly different. Microsoft apparently took one and a half years to develope it and it shows in it’s maturity as a browser.The down side is that there is still a shovel load full of web users that still have IE6 and IE5, so what to do if you make a website and want to see if it works in the major browsers, not just the browser that you happen to have installed on your development system.
You can run side by side installations of Firefox and Opera, but IE has always dragged the chain on this, due to IE being so heavily integrated into the operating system.
When I upgraded to IE7 I definately at least wanted to be able to have IE6 on the same machine. Well the dodgey hacks and workarounds that you will find if you do a web search on the topic, just didn’t work for me. Mostly they didn’t address that once you upgrade to IE7 the underlying DLLs that drive the browser are not backward compatible. So a cutdown version of IE6 just isn’t good enough for a true result.
Microsoft have finally acknowledged this and now have released a special IE6 virtual machine image to handle just this. Seems like massive overkill, but it works so I can’t complain.
Check out the Microsoft MSDN blog about IE6 and IE7 running together, and go and sort out your IE6 and IE7 on the same machine problem once and for all.
Of course the other alternative is if you have multiple PCs lying around you can have a separate machine setup with each IE. Which I have also done.