In issue #1 user expressed his concern about this already and I have to agree 
with him/her.
It would be very suggested to implement a fallback scenario.
For example - order could be provider when creating TSMBios class:
WMI first, but if error occured then fallback to WINAPI.
or
WINAPI first, but if GetSystemFirmwareTable function was not found then 
fallback to WMI.

When using WMI an error can occur if application is running on limited account 
(guest for example) - access denied.

Compiler directives could be used to force only WMI or WINAPI with no fallback 
scenario.