Cannot Install SQL Server 2005 Standard WinXP Pro SP2

Hello,


I have SQL Server 2000 Developer Edition already installed. Before starting
the SQL Server 2005 Standard setup, I exited the SQL server agent running in
my system tray.


I am logged on as Administrator and no other desktop apps are running. SQL
Server 2005 Setup reports several "Setup failed." error messages after the
install. I am choosing (for now) ONLY the workstation tools and books online
check mark. The installation presents a screen that says that these products
were successfully installed ("Setup finished"):
- MSXML6
- OWC11
- SQL Server Backward-Compatibility Files
However, these items have a red x next to them:
- SQL Server Books Online
- SQL Server Support Files
- SQLXML4
- SQL Native Client
- Workstation Components, Books Online, ...


My Setup log file terminates with a few messages--one of which contains the
words "Configuration failed." (This is the ONLY mention of the word "fail" in
the Setup log--see the excerpt below.)


Any ideas??? I'm stuck without SQL Server 2005 running so this is a
productivity killer for me.

More info: Here is what I have done, to no avail:


1) Installed the OWC11 components using a direct download from Microsoft.
That install worked. But when it runs again from the SQL Server 2005 DVD, it
fails.
2) Logged on not as a user with Admin rights, but as ADMINISTRATOR. Same
results--the SQL Server 2005 Standard setup failed.
3) Installed SQL Server 2005 Express successfully. Afterwards, tried again
to install SQL Server 2005 Standard, and that setup failed.
4) Cleared registry values for SQL Server 2005 under HKLM.../Software as
described in KB article. Also deleted the installation folder ...90. Tried
again to install SQL Server 2005 Standard, and that setup failed.
5) Tried the 180-day trial of SQL Server 2005 Enterprise--to no avail. Same
results.


Found error logs but they did not help me pinpoint the root cause for the
failed installation.


Thank you,
-- Jonathan


SQLSetup0004_zzzzz_SQLNCLI_1.log Excerpt:
============================+
MSI (s) (60:90) [12:01:14:390]: Note: 1: 1729
MSI (s) (60:90) [12:01:14:406]: Product: Microsoft SQL Server Native Client
-- Configuration failed.


MSI (s) (60:90) [12:01:14:406]: Cleaning up uninstalled install packages, if
any exist
MSI (s) (60:90) [12:01:14:406]: MainEngineThread is returning 1603
MSI (s) (60:68) [12:01:14:406]: Destroying RemoteAPI object.
MSI (s) (60:9C) [12:01:14:406]: Custom Action Manager thread ending.
=== Logging stopped: 2/8/2007 12:01:14 ===
MSI (c) (8C:4C) [12:01:14:406]: Decrementing counter to disable shutdown. If
counter >= 0, shutdown will be denied. Counter after decrement: -1
MSI (c) (8C:4C) [12:01:14:406]: MainEngineThread is returning 1603
=== Verbose logging stopped: 2/8/2007 12:01:14 ===