Classic ASP and IIS 7.0

Trying to run Classic ASP on a Vista machine you will get an error when trying to use a Microsoft Access database.

Microsoft JET Database Engine error '80004005' Unspecified error

You need to edit the file ApplicationHost.Config (C:\Windows\System32\InetSrv\Config\) the section where: (Layout might vary slightly)

<applicationPoolDefaults>
<processModel identityType="NetworkService" />
</applicationPoolDefaults>

Change to:

<applicationPoolDefaults>
<processModel identityType="NetworkService" loadUserProfile="false" />
</applicationPoolDefaults>

Now all your Classic ASP applications will work on your machine.

Background Info
ApplicationHost.config is the root file of the IIS 7.0 configuration system. It includes definitions of all sites, applications, virtual directories and application pools, as well as global defaults for the web server settings (similar to machine.config and the root web.config for .NET Framework settings).