Error message when you try to reinstall Microsoft Dynamics CRM 3.0 after you uninstall Microsoft Dynamics CRM 4.0: "Microsoft.Crm.Setup.Server.ConfigureServiceVirtualDirAction failed"

Consider the following scenario. You upgrade from Microsoft Dynamics CRM 3.0 to Microsoft Dynamics CRM 4.0. Then, you use Add or Remove Programs in Control Panel to uninstall Microsoft Dynamics CRM 4.0. Next, you try to use the installation wizard to reinstall Microsoft Dynamics CRM 3.0, and you use the default Web site that is listed in the installation wizard. In this scenario, you receive the following error message:

This problem occurs because some files remain on the Web site after you uninstall Microsoft Dynamics CRM 4.0.

To work around this problem, use one of the following methods.

Method 1

Manually remove the Microsoft Dynamics CRM 4.0 Web site. To do this, follow these steps:

1. Log on to the computer that is running Internet Information Services (IIS).
2. Click Start, point to All Programs, point to Administrative Tools, and then click Internet Information Services (IIS) Manager.
3. Expand the computer name, and then expand Web Sites.
4. Right-click the Microsoft Dynamics CRM 4.0 Web site, click Stop, and then click Yes.
   
   Note By default, the name of the Microsoft Dynamics CRM 4.0 Web site is Microsoft Dynamics CRM.
5. Right-click the Microsoft Dynamics CRM 4.0 Web site, and then click Properties.
6. Click the Home Directory tab, click DefaultAppPool in the Application pool list, and then click Remove.
7. Click the ISAPI Filters tab, click CRM.Default.Addon isapi, and then click Remove.
8. Click OK.
9. Expand Application Pools, right-click the Microsoft Dynamics CRM 4.0 application pool, click Delete, and then click Yes.
   
   Note By default, the name of the application pool is CRMAppPool.
10. Close IIS Manager.

Method 2

Create a new Web site, and then use the new Web site when you reinstall Microsoft Dynamics CRM 3.0.