You'll need to install the PHP soap extension as well as PHP pear package. This depends on how you installed PHP, so you will need to look in the documentation that came with your PHP installation for more information.
if you have tried installing PHP on Windows through an installable msi file, then these options are available in the "choose items to install step" under "Extenstions" for SOAP and under "Extras" for PEAR
I'm also facing the same problem. I'm using PHP5.2 win installer.
The SOAP issue was solved when installed it from the package extensions but the PEAR issue didn't be solved when installed it from the extra items.
there was a problem in the go-pear.phar file that i got with the PHP5.2 windows installer. u can try to get the new go-pear.phar file from a latest snap of your php installation and replace your existing go-pear.phar in the PEAR folder with the new one from the snap.