Holy cow, I wrote a book!
A customer reported an incompatibility in Windows 7:
If A: is a floppy drive and they call
and there is no disk in the drive,
the LoadLibrary call fails
with the error
Previous versions of Windows failed with the error
Both error codes are reasonable responses to the situation.
"The module couldn't be found because the drive is not ready."
Programs should treat a failed LoadLibrary
as a failed library load and shouldn't be sensitive to the
precise reason for the error.
(They can display a more specific error to the user based on the error
code, but overall program logic shouldn't depend on the error code.)
Fortunately, the customer discovered this discrepancy during their
pre-release testing and were able to accommodate this change in their
program before ever releasing it.
A sigh of relief from the application compatibility team.