Hi
Most likely because you have an too old version of MDAC installed.
From
http://www.microsoft.com/technet/security/Bulletin/MS04-003.asp
<quote>
Prerequisites
This security update requires that you have any one of the following
MDAC versions installed:
MDAC 2.5 Service Pack 2
MDAC 2.5 Service Pack 3
MDAC 2.6 Service Pack 2
MDAC 2.7
MDAC 2.7 Service Pack 1
MDAC 2.7 Service Pack 1 Refresh
MDAC 2.8
</quote>
I suggest you upgrade to e.g. MDAC 2.8 and see if it solves the problem,
you can find the download link here:
http://www.microsoft.com/data
If KB832483 then is installing successfully, after the reboot offered by the
update, you should also run the following command from Start\Run:
regsvr32.exe "%ProgramFiles%\Common Files\System\Ole DB\oledb32.dll"