MS Office 2003 Pro and Windows 7 Pro

I have tried every which way to make MS Office 2003 Pro fully compatible with my new Win 7 Pro but there is always something that is not fully compat. I know Office 2003 is no longer supported but that is not in any way part of my question. My question is:

Has anyone seen any document anywhere explaining why Office 2003 is not fully compat with Win 7 Pro?
For example:
1. Windows wants to configure this, that and the other every time I start any component of Office 2003.
2. When opening a file, the selected file's title does not appear in the selected-file-box in the bottom;
3. Office 2003 is the only program that will not recognize a wheel-click as a double-click; all my other programs, without exception, do.
4. And such like annoyances.

I am using OpenOffice and am quite ready to buy MS 2013 or 365, so this question is only to satisfy my curiosity.

I thank in advance one and all for all info, opinions, gossip, guesses, advice, etc.

Thank you Ranger4. No, I have no other version of 2003 Pro installed on my machine. Incidentally, I tried installing it on my wife's Windows 7 Home Premium and it behaves exactly as it does on my 7 Pro.