After Installing PHP 5 using the Windows installer on Windows 2003 you may find that IIS displays a “Page Not Found” 404 error for every .php page. This is a perplexing error because is it not actually a real 404 error. The file is really there, but IIS is unable to process it based on how the installer configures the extension mapping. Instead of providing any useful information or even a 500 error; however, IIS throws out a 404.
Steps to Fix the Problem:
Before you troubleshoot further, you may want to read #5 about how the Application Pool effects PHP configuration changes.
1. Replace the old DOS format path to the PHP Executable with a full path w/ quotes
2. Move php.ini to C:\Windows
3. Edit php.ini to set cgi.force_redirect = 0 (only necessary for CGI mode)
4. Make sure php-cgi.exe and/or phpisapi.dll are included in Web Service Extensions
5. Recycle the Application Pool
1. Replace the old DOS Path Format
The default path to PHP is C:\Program Files\PHP. When creating the IIS extention mapping, the PHP Installer uses the old DOS format path to the PHP ISAPI or CGI executable such as “C:\PROGRA~1\PHP\PHP5IS~1.DLL”. IIS does not seem to like this format.
One simple solution for this is to simply reinstall PHP to C:\PHP, or another location that doesn’t use long filenames. This will generally save you a lot of grief as PHP and its installer do not seem to handle windows long file names consistently.
If you prefer to keep things in Program files, go to the IIS Extension Mapping screen and locate the value for “.php” (See screenshot above). Click the browse button, select the executable and put quotes around it the entire path. So the value for this field should look like this “C:\Program Files\PHP\php5isapi.dll” (WITH the quotes around it). If you have installed PHP in CGI mode instead, the file name would be php-cgi.exe instead of php5isapi.dll
While you’re at it you may want to check the box for “Verify that file exists” as well. This allows IIS to handle actual missing pages (ie broken links) and return a 404. Otherwise IIS will just pass the request to PHP without verifying the .php file really exists and PHP throws a CGI error when the file isn’t found. People seem to have inconsistent results with this setting.
If you recycle the app pool at this point (see step #5) you *may* solve the 404 error depending on what extensions you installed or whether you had re-run the installer and changed stuff. However, you may still have issues changing php.ini settings in which case keep reading.
2. Copy php.ini to C:\Windows
The PHP installer creates a php.ini file for you based on your selections in the setup process. However the installer saves the file in C:\Program Files\PHP. The problem is that PHP is looking in C:\Windows for the .ini file. So, you need to move the file php.ini to C:\Windows. This may be confusing because PHP seems to run fine. But if you look closely at the phpinfo() output, you may find that php.ini file is not being loaded and all default settings are being used.
One of the critical things when configuring PHP is to actually edit the .ini file that is being used by PHP. The installer creates a worthless file in a location that PHP won’t read and so you may waste a lot of time editing this file. PHP pretty much universally will check the Windows folder for php.ini on all varieties of Windows, so my advice is to use that location and delete any other php.ini files that are hanging around..
3. Set cgi.force_redirect = 0 (Only necessary for CGI mode)
Various people report that you need to edit php.ini and set:
cgi.force_redirect = 0
I haven’t noticed this setting having any effect on my installations, but many people claim it is necessary when you are running PHP in CGI mode. This setting will have no effect if you are running in ISAPI mode.
4. Make sure php-cgi.exe and/or phpisapi.dll are enabled in Web Service Extensions
In IIS Manager, click on “Web Service Extensions” This includes a list of all dll and exe files that IIS is allowed to execute. The extension mapping that is specified for .php files must also be added here. I prefer to just add both php-cgi.exe as well as php5isapi.dll here and enable them both so that if I don’t need to worry about it again.
If the handler is already in the list, make sure that it is “enabled” as well. The enabled services have a green overlay on the service icon.
Lastly, confirm that the file path is exactly the same here as it is in your .php extension mapping configuration. That includes the dos path formatting. If you use junctions, you need to be using the same path in both places. IIS seems to check the path rather than the executable. It will not recognize if you use a slightly different path, even if they both point to the same executable.
5. Recycle the Application Pool
In order for any PHP configuration changes to take effect in Windows 2003, you need to recycle the Application Pool. If you have made changes to php.ini and they don’t seem to take effect, this is likely the reason. Among other things, the pool caches PHP settings and you need to clear it before new configuration settings will take effect. You’ll read people telling you to restart IIS (which doesn’t recycle the app pool) or even reboot your machine (which is overkill). You don’t need to do either of those. Just right-click on the DefaultAppPool in the IIS management interface and “Recycle” is one of the options.
If I’m having trouble with the ini file, I like to have a typical phpinfo.php file on the server while I make some arbitrary change to the php.ini file (like the session timeout or the max upload size). I refresh phpinfo.php and verify that my changes are taking effect. You can also check the Windows Event logs under “System” which will sometimes report errors in the php.ini file.
Notes regarding re-running the PHP installer to make changes:
The PHP installer does not really handle changes all that well. For one thing it will overwrite the path to the PHP executable w/ the old DOS format so you need to fix that after you run it.
The 2nd thing is that it will write changes to C:\Program Files\PHP\php.ini – regardless of the fact that PHP is actually looking at C:\Windows\php.ini
If you had previously moved php.ini to the windows folder, when you run the Change installation feature, it will create a fresh php.ini file that only incorporates the most recent changes. (ie, if you had 10 extensions enabled and you make a change to enable 1 more, your new php.ini file will only have the 1 enabled and the previous 10 will no longer be enabled)
One way around this is to temporarily move C:\Windows\php.ini file to C:\Program Files\PHP. Then run in installer to make changes. The installer will write changes to php.ini in that location. Then, move php.ini back to C:\Windows.