Can't install Office 2007 SP2

[Mitch]

I downloaded the 290 MB file to manually update Office 2007 to SP2. However,
when I run that huge file, it generates an error message saying "The
detection falied, this can be due to a corrupted installation database."

I then tried to reinstall Office 2007 from the original installation file (I
bought it online and downloaded the installation file) but that failed, too.
That error message read only "Setup did not complete successfully. We are
sorry for the inconvenience. An error occured [sic] during the installation,
and setup was unable to complete. Please tell Microsoft about the problem." I
clicked "Send Error Report" and also looked at the log file that was sent.
The last few lines of the log file read:

Error: Type: MsiOpenDatabase call failed.. MsiAPICallFailure ErrorCode:
110(0x6e).
Error: Type: MsiOpenDatabase call failed.. MsiAPICallFailure ErrorCode:
110(0x6e).
Error: Type: MsiOpenDatabase call failed.. MsiAPICallFailure ErrorCode:
110(0x6e).
Catalyst execution finished: 05/02/2009 12:07:31. Return code: 30050.
Exception caught: MsiAPICallFailure.
PERF: TickCount=32508828 Name=RunSetup Description=End function
====================================================

I am afraid to totally uninstall Office 2007, as I am afraid that I won't be
able to reinstall it once it is gone.

How can I get SP2 installed?

 

[DL]

Have you first tried Office Diagnostics, from the dvd or any Office
component?