Heads up: the latest IE7 Beta 2 Preview Build seems to include the activex 912945 update described here:
Ok, so you've downloaded the latest build of IE7 and want to install...
Please, disable antivirus and crashguards, antispyware products etc. Shut down all other programmes, including those that run via System Tray, but do NOT disable your firewall.
Disable automatic updates... I promise, you'll thank me for it.
Uninstall any previous build of IE7 and reboot twice - yes, twice. You may experience a svchost.exe crash the first time you reboot. Ok it and continue on. You shouldn't see the crash during the second reboot.
Note: If you did not disable automatic updates before now, AU will trigger and start downloading updates after IE7 has been removed and the system rebooted. If your system is set to download *and* install updates, let it finish and reboot twice. Do NOT try to install IE7 while this is happening.
If, on the other hand, you have AU set to download but not install updates, just ignore it. Let it download, but do not install. It is safe to install IE7 while the updates are downloading if you do not attempt to install the updates during or after the IE7 installation, but it can get a tad messy. When you reboot your PC when the IE7 installation is finished you may see an error about an 'extracting files' program having to be closed slowing down the restart.
Ok, so now we're ready to install. Things may seem slow between 45% and 48% complete, so be patient. The install will sit there, your hard drive will crunch away, and the percentage counter may not move for what feels like a very long time. Then, suddenly the percentage counter will jump forward and installation will finalise.
Reboot twice before re-enabling automatic updates and your antivirus and crashguards.
The first time you start IE you will be redirected to http://runonce.msn.com/runonce2.aspx. Make any changes you want to make then scroll to the bottom of the page where you will see these options:
Many people with smaller monitors have not spotted the options pictured above. The page should not appear more than once, but if it does, use the bottom link.