The following bug has been logged online:

Bug reference: 1419
Logged by: Joseph Donahue
Email address: joseph (AT) odonahue (DOT) com
PostgreSQL version: 8.x
Operating system: Win2K SP4
Description: Uninstall v8.0 removes files v8 Beta4 is dependant on.
Details:

I installed release v8.0 in a seperate directory from my beta4 installation
and then uninstalled it. This removed at least one of the shared files the
beta was dependant on. When I try to start the beta as a service I get
"pg_ctl.exe - Unable To Locate DLL" pop-up with the following information:

The dynamic link library libpq.dll coud not be found in the specified path
C:\Tools\PostgreSQL\8.0.0-beta4\bin;C:\WINNT;... (etc., rest of the path
deleted).

I know I should not speculate, but there is some risk that someone will
install the release and then uninstall a beta (after configuring and testing
the release) and break the release installation.

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Was beta4 installed by the MSI installer? It's really supposed to take
care of that. libpq.dll should be in SYSTEM32, and shouldn't be removed
until *all* instances are uninstalled. I have tested this several times,
and it has always worked in my tests.

Do you ahve any other software installed that may have provided a
libpq.dll`?

//Magnus

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