Migrating to IIS 7

Just received my new laptop last week. I decided to go ahead and install Vista Ultimate 64-bit (I have 4 GB of RAM - the 32 bit version only sees 3).

Overall, considering how many rants I've read about Vista, I have to say I'm quite pleased. My machine is pretty speedy, apps are pretty snappy. The only headache was to get our web app to run on IIS 7 (64-bit).

Here are a few things to keep in mind:

- After installing IIS, it looks like you're ready to go. .Net is integrated, all versions of the framework are already installed (except 3.5 of course). Your web.config files are recognized. But for some reason, you won't be able to run any ASP.NET pages. That's because by default, IIS installs the bare minimum. You'll need to go back to the "Turn Windows features on and off" admin console and install ASP.NET support.

- Win 32 compatibility: we're not yet going to switch to x64 platform on production. Thus we're going to keep compiling for Win32. This caused more problems as IIS runs 64-bit apps by default. You'll need to check the "Enable 32-Bit Applications" option on your application pool.

- ISAPI filters: we're using Helicon's ISAPI_Rewrite for URL rewriting. Yes, I know we could now get rid of it and write a .Net HttpModule to deal with this, but we're not quite ready to move to IIS 7 on production. So to get this to work, I had to install a few more add-ons in IIS. More here. Because we're using 32-bit compatibility mode, we installed the 32-bit version.

- VS debugging: make sure you install the "Windows Authentication" IIS module for debugging to work in Visual Studio. Also, set the "manage pipeline mode" to "Classic".

- User impersonation: the default IIS users are now "Network Service" (just like Wind Server 2003) and "IIS_IUSRS".

- Configuration Settings: certain sections (such as HTTPHandlers and HTTPModules) are now locked by default. You'll need to change that setting in "c:\windows\system32\inetsrv\config\applicationHost.config" and set the "overrideModeDefault" attribute to "Allow" on the sections you want to allow.

- I had to remove all the default assemblies (System, System.Web etc...) from my Web.Config compilation section for the site to work as those were duplicates of the assemblies specified in the master web.config file. Not sure yet how this will impact the site once released on IIS6.

I might have forgotten a couple of things, but at least this should put you on the right track.