If you are developing websites, or simply don’t want to change browsers, you can stop Microsoft automatic update from installing IE 7 or IE 8 by installing the following updates from Microsoft:
Once run, they will extract files to the location of your choice, then you have to use an elevated command prompt and run the command with a /B switch (block) as follows:
IE70Blocker.cmd /B
You can revert to the normal state (allowing Microsoft / Windows Update to replace your browser) as follows:
IE70Blocker.cmd /U
Note that in order to keep IE6 you need to run both 7 and 8 blockers.
Then, you can keep your system completely up to date whilst maintaining the old-school browsers!