Exception EOleException in module vclado50.bpl

hi,
I am using delphi 5.0 with SQL-server7 as the backend database.  I have
been getting the error
message "Exception EOleException in module vclado50.bpl at 0000A430.
Provider cannot be
found. It may not be properly installed.".  I have installed Delphi 5.0
(and the upgrade) as well as ADOexpress
(and the 2 upgrades).  Can anyone help me as to determine what this
problem is.  I am very new to
Delphi and have inherited someone else's project.  I was wondering as to

what version of MDAC should
I be using as well.  Thanks in advance.
Tan