IE7 needs Service Pack 2.
Service Pack 2 does horrible things to a computer. For example, I have two computers with the same exact hardware specs. Same services running. The SP2 computer runs MUCH slower than the SP1 computer. I'm not just talking about network speed (I know about the TCP connection limitation in SP2 (from 65k connections down to 10 connections! (and I know about the tcpip.sys hack to fix it)). I'm talking about launching programs, opening my computer, etc. All are much slower with SP2.
So, unless someone can find me an IE7 that runs with SP1, I won't be installing it. Besides, Firefox does everything I need on a daily basis, and IE6 is there for backup, in case there's some stupid ASP site that I need to view that just wont work right in Firefox (damn non-standardization!).