Problems opening office documents in SharePoint 365

I was trying to open a SpreadSheet from a SharePoint 365 site only to keep getting this error message:

The document could not be opened for editing.  A Microsoft Foundation compatible application could not be found to edit the program.

Which is really odd since I do have excel installed on my machine.  I found lots of blog posts suggesting to verify that certain SharePoint add ons are enabled in IE to ensure you are using the 32 bit version of IE, ensure office is installed, but nothing really useful as all I could check yes to all their suggestions: (http://community.office365.com/en-us/forums/175/t/59242.aspx).

Turns out that the activeX control that is used by SharePoint 365, and probably SharePoint on prem although I don’t know for sure, comes with the Office install.  So the suggestions were on the right track, you need to have office installed…but here is the kicker.  It all depends on which version of office you installed 32 bit or 64 bit.  If you have installed the 64 bit version of office, you need to run the 64 bit version of IE for this activeX control to work properly and vise versa.

Now you know.