BUG #3797: b4 msi installer fails when b3 is still installed

The following bug has been logged online:

Bug reference: 3797
Logged by: thomas haegi
Email address: me(at)alternize(dot)com
PostgreSQL version: 8.3b3/b4
Operating system: Windows 2003
Description: b4 msi installer fails when b3 is still installed
Details:

probably due to the fact that the installer's version is tagged as 8.3 and
not 8.3bx, it won't allow you to install pgsql b3 and b4 side-by-side:

"Another version of this product is already installed. Installation of this
version cannot continue. To configure or remove the exisitng version of this
product, use Add/remove Programms on the Control Panel."

it is hower possible to have 8.2 and install 8.2b4 side-by-side.

it would make beta-tests a bit more convinient (even more :)) if one
wouldn't have to install pgsql manually in a win32 environment when two beta
versions should run concurrently.

as a sidenote, the current win32 builds on postgresql.org do not have the
upgrade.bat file included although the readme.txt says so.

regards,
thomas