&reftitle.install; To build the ibm_db2 extension, the DB2 application development header files and libraries must be installed on your system. DB2 does not install these by default, so you may have to return to your DB2 installer and add this option. The header files are included with the DB2 Application Development Client freely available for download from the IBM DB2 Universal Database support site. If you add the DB2 application development header files and libraries to a Linux or Unix operating system on which DB2 was already installed, you must issue the command db2iupdt -e to update the symbolic links to the header files and libraries in your DB2 instances. ibm_db2 is a PECL extension, so follow the instructions in to install the ibm_db2 extension for PHP. Issue the configure command to point to the location of your DB2 header files and libraries as follows: The configure command defaults to /opt/IBM/db2/V8.1. If you are using the ibm_db2 driver with Microsoft Internet Information Server (IIS) you may have to do the following: Install DB2 with extended operating system security. Add the PHP binary path to the PATH system environment variable (default C:\php\). Create another system environment variable equal to the path where the PHP.INI file is located (eg: PHPRC = C:\php\). Add the IUSR_COMPUTERNAME to the DB2USERS group.