Perhaps you could install 10, play with it, then do restore to go back to 9 with System Restore:
http://windows.microsoft.com/en-US/windows7/What-is-System-Restore>>You've never been able to run multiple versions of IE on the same box.
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>Hmm, I didn't know that.
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>>Also, in the time it took you to post your install question here, you could have googled it.
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>It was just a comment in passing, not something I was really inrerested in doing at that moment.