The page: How to Install PHP 5.2 on IIS 7and Windows Vista (and a few others) reference a mysterious php5isapi.dll which is not in the Windows install, or the zip files:

php-5.3.2-Win32-VC9-x86.zip - VC9 x86 Thread Safe
php-5.3.2-nts-Win32-VC9-x86.zip - VC9 x86 Non Thread Safe

There was another post on stackoverflow that said it's obsolete and replaced by "fastapi" but no instructions mention this.

I did find a php.dll in the zip file. Can I use that instead of php5isapi.dll?

It's very frustrating trying to install basic PHP5 on Windows with MySQL.


If I recall correctly, FastCGI is the recommended interface on Windows starting with 5.3.

Is there a reason you can't switch to FastCGI?

As for the DLL, I recall something about the switch to VC9 that made it fun/complex. Maybe there us a VC6 build somewhere?

  • No reason... I can probably switch. I'm a newbie and just don't know the right way to proceed. I'll try FastCGI! – Pete Alvin Jun 13 '10 at 10:29
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    Turns out that they indeed dropped all ISAPI support in 5.3 news.php.net/php.internals.win/166 – Charles Jun 13 '10 at 20:35
  • Just add the "CGI" feature to the IIS component using add/remove windows features and you'll be on the right path – Mark Henderson Jun 14 '10 at 4:54

Fast CGI would be best option and Please Use Non thread Safe Version of PHP 5.3 installer/Zip as it is much compatible with windows.

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