barnesbk wrote:On php.net regarding upgrades, it just says to run the .msi installer and the program would use all the setting from the old version, then delete it.
Seeing as you've already got PHP set up, consider just using the .zip file.
I'll write this assuming that PHP is installed in "c:\php". I've always just used the zip archive, so I don't know where the installer puts it; and what follows is my typical upgrade path.
Unpack the zip archive to "c:\php-5.2.9". Rename c:\php-5.2.9\php.ini-dist" or "...-recommended" as appropriate to "php.ini". Compare it with "c:\php\php.ini" and in "php.ini" change whatever needs changing (this is just a revision release so there's nothing really significant except your own customisations).
If you're using third-party extensions like XDebug or something from PECL, copy them from "c:\php\ext" to "c:\php-5.2.9\ext". Copy the PEAR and tmp directories across, too, if you have them (sometimes I just copy the old directory tree right on top of the new one, specifying "no to all" when asked about filename collisions).
Then rename "c:\php" to "c:\php-5.2.3" and "c:\php-5.2.9" to "c:\php" and restart your server. After a while, when you're confident that 5.2.9 is running happily, you can delete c:\php-5.2.3. If it's all falling over you can rename "c:\php" back to "c:\php-5.2.9" and "c:\php-5.2.3" back to "c:\php" and you'll be back to a 5.2.3 installation, and you can take your time tracking what's blown up.