The first step is to actually install IIS7. Unlike in Windows XP, IIS isn’t installed by default. That’s great, but it can be kind of hard to find it when I need it.

You’ve got to click this link that says “Turn Windows features on or off” which will (after some time) bring up a big tree of features you can check or uncheck.

You’re going to want most of “World Wide Web Services”. If you are also interested in installing PHP, make sure everything I’ve circled in red is checked. I just added everything to be safe. What’s important is that you have the ISAPI and CGI stuff. I also checked the IIS6 compatibility bit so that installers for things like PHP might have a better chance at automatically configuring things (fat chance).

At this point you can start dropping things into C:\inetpub\wwwroot and everything should be peachy. I don’t put my sites there since I have them checked out into various folders in my Documents folder. So I need to create some virtual directories to point to my sites. This probably won’t work off the bat – you’ll get 403 errors that complain about wrong permissions or something. You need to make sure that the “IIS_IUSRS” and “Authenticated Users” users have read access to the directory. I’m not sure why “Authenticated Users” needs to be there but it made it work. Make it look like this:

At this point your folder should be accessible from the virtual directory, and any ASP.NET stuff will probably work. If you’re not interested in installing PHP, you can stop here.

Installing PHP on IIS7

PHP doesn’t really play well with IIS. However, we can get it going good enough for local testing of your PHP code. First, go install PHP5 from php.net. Choose to install it as an ISAPI extension for IIS, but don’t worry too much, since it won’t work anyway. Now open up IIS Manager. If you’ve followed the steps above (specifically, selecting the correct “Windows features”), your IIS manager should look something like this:

What’s important is that you have the parts outlined in red – the “CGI” icon, the “ISAPI Filters” icon, and the “ISAPI and CGI Restrictions” icon. Those mean the right bits are installed.

Now double-click the “Handler Mappings” icon, and click “Add Script Map…” Fill out the form like this:

Make sure it’s pointing to your real copy of php5isapi.dll. At this point your Handler Mappings screen should look like this:

Also make sure that your “ISAPI Filters” screen looks like this:

If not, add PHP like this:

If you’re running the 64-bit version of Vista like I am, there’s one last thing to do in IIS Manager. Since the PHP ISAPI extension is a 32-bit app, you’ll need to set your app pool to run in 32-bit mode. I’ve already written one blog post on this (to get MySQL working with ASP.NET), and the instructions are the same. Basically open up the app pool’s advanced settings dialog and flip it to 32-bit mode:

If you forget this you’re likely to get errors that look like “Calling LoadLibraryEx on ISAPI filter “C:\Program Files (x86)\PHP\php5isapi.dll” failed”.

If you load up your PHP files you’ll probably get something like “failed opening required” blah blah. This is because the PHPRC environment variable isn’t set correctly by the PHP installer. We’ll have to do it ourselves. Go to the Control Panel and search for “env”:

Now add a System environment variable like this (point it at the directory PHP is installed):

At this point you must reboot your computer to get the environment variable to take effect. Annoying but true. At this point PHP should work, more or less.

I still have some problems with PHP the way I’ve described configuring it. The most obvious is that the IIS worker crashes every once in a while:

I suspect reconfiguring PHP to be run as a CGI handler instead of an ISAPI module would help here, but it hasn’t been annoying enough to make me go change it. Another avenue to investigate is the new FastCGI support that’s available for IIS7.

The other problem I’ve had is that I have a handful of image files in one of my sites that are managed by Subversion and get locked and unlocked pretty frequently. After I’ve committed an image, it loses its permissions and can’t be served from IIS anymore, and I need to go reset the permissions. That’s pretty annoying, and I’m not sure if it’s a bug in Subversion or in one of my SVN clients (TortoiseSVN and Subclipse).

At least this setup works enough to try things out quickly. I hope it helps anyone else who’s struggling with one of these setups.

Update: You might want to try out the new Microsoft Web Platform Installer which purports to set up PHP along with anything else you might need.