PEAR：无法打开输入文件：文件

I've tried everything I know to solve this, but this error still occurs.

C:\windows\system32>pear install MDB2-2.5.0b5
Could not open input file: Files

C:\windows\system32>pear
Could not open input file: Files

Im using PHP 5.2.17 with Apache 2.2.

Everything seems fine with php.ini and pear.bat.

I have been able to find the error, on the pear.bat that i executed on the final part where it shows -d include_path=\".;%PHP_PEAR_INSTALL_DIR%" i simply removed the \ so the right one is:

-d include_path=".;%PHP_PEAR_INSTALL_DIR%"