"pear install mailparse" command returns extension not installed error - at wit's end, please help

Hello, I have just installed Apache 2 and PHP 4.3.10 on my Windows XP computer. I followed the relevant installation tutorials provided respectively by Apache and PHP documentation. I enabled the mbstring extension, and when I load a PHP page with php_info() I get a section on mbstring in it, so the extension is indeed loaded. However, when I try to install the mailparse extension using PEAR I get the following: C:\Tools\php4>pear install mailparse downloading mailparse-2.1.1.tgz ... Starting to download mailparse-2.1.1.tgz (35,883 bytes) ..........done: 35,883 bytes 'mbstring' PHP extension is not installed mailparse: Dependencies failed Moreover when I type: pear package-dependencies mailparse I get: This package does not have any dependencies. -p I really need to use this package. Please explain what is going on, I am at my wit's end. I might add that despite my having put the path c:/tools/php4/pear in the include_dir directive of my PHP.INI, when I install pear using go-pear I get this warning after a few steps: WARNING! The include_path defined in the currently used php.ini does not contain the PEAR PHP directory you just specified: <C:\Tools\php4\pear> If the specified directory is also not in the include_path used by your scripts, you will have problems getting any PEAR packages working.

Current include path           : .;c:\php4\pear
Configured directory           : C:\Tools\php4\pear

Currently used php.ini (guess) : Press Enter to continue: Here is, however, my PHP.INI relevant information: include_path = ".;c:\tools\php4\includes;c:\tools\php4\pear" I am officially out of ideas. I read all the installation manuals, looked up the error message, all in vain. Don't know what I'm doing wrong. There is no documentation that I know of that talks about this problem. Please don't send links to more documentation, this question has a lot of points in for someone who will tell me from A to Z what is happening. I need to understand this stuff. Thanks! Philippe