Error on Installing under Windows Vista leads to inability to uninstall

[Stephan G <stephan-g@xxxxxxxxxxxx>]

Hello.

I have tried to install the following on my Windows Vista Home Premium 
System:

	php-5.2.3-win32-installer.msi

It has the following md5 sum, taken locally on my system:

	4d042f649d9c264477e1b421c64c6435

Installation seemed to go as expected.  However, near the end of the 
installation process, I received a dialog window titled "PHP 5.2.3 
Setup" with only an "OK" button and the following message:

	"The installer has encountered an unexpected error
	installing this package.  This may indicate a problem with
	this package.  The error code is 2738."

I pressed "OK", my only option, and then got to the page on the setup 
wizard with the "Finish" button.  I hit the "Finish" button, was met 
with a dialog window with just an OK button with the message:

	"Fatal error during installation".

It seems that PHP was put on my system, and the path was set up 
correctly.  Some simple tests indicate it is working, however, since I 
am a careful sort, I thought I would try to uninstall and start over.

The trouble is that I can't.  I can use the "Repair" option from 
ControlPanel->ProgramsAndFeatures->PHP, and it seems to "repair" without 
comment, but if I try to uninstall the software, or "Change" it in any 
way, I get the same two dialog boxes shown above, and the software does 
NOT uninstall.  This makes me uneasy.

I would appreciate help with any of the following (roughly in my 
priority order):

	1.  How can I uninstall this and remove it from my system?

	2.  What is error code 2738 and what does it mean?

	3.  What steps might I take subsequently to install without
		incurring this error?

Thanks in advance for any assistance.

	-Stephan G