The file OLMAPI32.dll is incompatible with Microsoft Outlook. Install Outlook again.

I started with a Windows Vista 64 bit home premium machine that included the free upgrade to Windows 7 when it came out. Since loading the windows 7 I have had nothing but problems with programs as diverse as Microsoft Outlook, and The entire Autodesk Inventor 2009 suite.
 Outlook simply crashes anytime someone sends me anything with an attachment in it. I get the ollowing message; The file OLMAPI32.dll is incompatible with Microsoft Outlook. Install Outlook again.
 I even removed outlook completly and reinstalled it, same thing, so I moved up to the Outlook 2010 Beta and it will work for a day, then right back where I started with the same crash.
 This is particuarly frustrating because as soon as Outlook gets the mail, it has removed it from my providers dserver, so eventhough I am unable to openit with Outlook, it is also no longer avalaible for anything else to open.
 I also own a copy of the Autodesk 2009 Inventor Suite that includes Autocad, Autocad Mechanical and Inventor 2009. I have no reason to upgrade this software because it is very expensive already and does what I want, but it willnot open at all on this operating system.
 As much as I hated Vista, I am about to have to format this drive and reload Vista on it unless I can locate a copy of XP somewhere I can purchase.
 Is there any answers coming for this obscene operating system that just says, "Upgrade your old software and don't bother me" when you ask for the answer to these problems?
And why would it not even allow Outlook to wortk with it? These are both actual Microsoft products for heavens sake! I don't think a Mac would have this trouble.