It’s very important to test your code on multiple browsers. Your audience could have any of them and you want your site to look the best no matter what, even if they have an ancient computer.
I’ve found several very good resources out there that have excellent free options.
I love this site. It actually gives you a remote desktop session with the OS and the browsers that you need to test.
NOTE: They used to have a free option, but it is gone now. Lowest cost is $19.95 for one month subscription.
Enter your URL and it returns screen shots of your site in over 80 browser and OS combinations. It even gives you the option of downloading them all as a zip file. Extremely handy!
Lastly, if your site is running into problems with older versions of IE, there is no easy way to install previous versions of IE on top of a more current version.
Tredo Soft has a program you can install called Multiple IE’s. It lets you do just what you couldn’t. Install previous versions of IE and test them on your computer. No more waiting for browser sessions on CrossBrowserTesting.com just to test IE! Here is the link:
If you’re using Vista, Multiple IE’s won’t work, however. You may need to use My DebugBar’s IE Tester: