Have OneNote running the whole time.
Run the PowerToy install all the way through.
The run the PowerToy install again, but just to the repair screen.
(creates the .msi file in a temp dir)
Then start Outlook and it won't prompt for the .msi
Cancel the second install.
If that doesn't work, then it is probably a toolbar conflict.
If possible, always install the PowerToy before any other
toolbars/plugins for Outlook.
Some more info from Chris Pratley's blog...
Note that many people have trouble installing this one. Some tips:
*
Not only do you need the .net framework you see in Add/Remove
programs (and that you probably got from Windows Update), you need to
install the "Outlook support for .net add-ins". This is in Office2003
setup - go to advanced customization, then in the tree that shows up,
open Outlook, and choose the first thing (.net programmability support)
*
If you get an error saying some *.msi file cannot be found,
open up the ZIP file that you downloaded, save the included *.msi on
your hard drive, and point the installer at that.
*
Even with these tips, if you have other Outlook Add-ins
installed you may still have some trouble getting it working. Sorry. Is
it Ok to say it is not a OneNote problem?