How I finally got IE7 Beta 3 installed

Had a test system (old laptop used for testing and traveling) with IE7 Beta 2 installed. I followed the steps outlined by the IE team for removing beta 2 and installing beta 3 and, of course, it didn't work. Could no stop the error about a previous version installed which prevented the install of beta 3.

Here's what finally worked after many attempts at various things (thanx to comments on the IE Blog):

1. Download and install Unlocker.
2. Right-click on the folder /Program Files/Internet Explorer and choose Unlocker
3. Select Unlock All from the bottom
4. Close Unlocker and delete the folder
5. Restart the system and install IE 7 Beta 3