03152015 UPDATE #1: I changed employers a few times since I wrote this post. In the interim I was unable to test any recommendations or investigate suggestions or help troubleshoot issues. I am back to a Notes client to use the corporate email system. I won't promise I can help, but I am in a better place to do so if I can.
03152015 UPDATE #2: I'm embarrassed by the spelling and grammatical mistakes in the original post. I think I corrected them all.
03152015 UPDATE #3: It's now IBM Notes.
I have Google Chrome installed on my work laptop. I have to install it as a few things don't work properly in Internet Explorer 9 (IE) yet.
Somewhere along the way Chrome became my Windows 7 installation's default browser. I didn't want that. I changed the Windows 7 default browser in "Default Programs" back to IE. The trouble was that one application, Lotus Notes 8.5.2, wouldn't open IE by default after changing back. I needed links in Notes opened by IE by default. Yet Notes wouldn't let go of Chrome for some reason.
One might and should question "Default Programs"'s utility in Windows 7, but that's a topic for another time.
I reflected on this state of affairs. It could be a philosophical commercial stand by IBM against Microsoft. It's not. They have better things to do.
Never attribute to malice that which is adequately explained by stupidity.
… or a lack of attention to detail based on assumptions.
Jorgensen's Corollary
The error is mostly likely due to poor assumptions by both Google Chrome and Lotus (now IBM) Notes that point to Windows 7 Registry entries that aren't updated when the default browser changes. It took me a long time to find the answer, but find it I did.
IBM described it here. In short, you need to:
Manually modify the following registry keys to remove Chrome and point it to iexplore.exe:
HKEY_CLASSES_ROOT\http\shell\open\command\ HKEY_CLASSES_ROOT\https\shell\open\command\ HKCU\Software\Classes\http\shell\open\command\ HKCU\Software\Classes\https\shell\open\command\
… and from there you're all set. If you want to change your browser to Firefox or back to Chrome I imagine you'll have to edit those entries again with the relative values. When I edited my registry (and you will make backups when you edit your registry, won't you?) only two of the four entries required changing.
Enjoy!