Since the release of vCenter Server 4.x VMware provides the capability to use a custom sysprep answer file when deploying a Windows based template.

After importing the custom answer file, the vCenter Server user interface presents the choice to use standard or custom network settings with the deployed virtual machine. These network customizations are not performed if the deployed virtual machine is Windows Vista or later.

When customizing a virtual machine, most users prefer to have vCenter Server build a sysprep answer file. The user interface provides the choice to customize options such as computer name, networking and SID, which are then applied to the virtual machine using Microsoft Sysprep.

Users can also use a custom sysprep answer file to customize a virtual machine with below steps:

1. From the vSphere Client Home page, go to Policies and Profiles and click VM Customization Specifications.
2. Click New.
3. In the Guest Customization wizard, enter a name for the specification and an optional description.
4. Select Windows from the Target guest OS.
5. Check Use custom SysPrep answer file.
6. Make sure Generate a new security identity (SID) is always checked and click Next.
7. Select the option to import or create a sysprep answer file and click Next.
8. Select the type of network settings (Standard or Custom) to apply to the guest operating system and click Next.
9. Review your settings and click Finish to save your changes.

The network customizations specified in Step 8 will not be performed to the deployed virtual machine. The network settings need to be specified in the custom SysPrep answer file in Step 7.

For example, using Windows System Image Manager, custom network settings can be configured using the Microsoft-Windows-TCPIP_*_neutral template.

For more information, see the Windows article Windows System Image Manager Technical Reference and Microsoft-Windows-TCPIP component document.
 

Note: For Pre-Vista Windows based virtual machines (Windows 2000, Windows XP, Windows 2003), the expected behavior is different:

• Custom sysprep network settings are applied if the user interface is set to use DHCP
• Custom sysprep network settings are not applied if the user interface is set to use static IP address settings.

SYSPREP UI     RESULT
------- --     ------
None    DHCP   DHCP
None    Static Static
DHCP    DHCP   DHCP
DHCP    Static Static
Static  DHCP   Static
Static  Static Static(UI)

vCenter Server Guest OS Customization feature has stopped supporting Pre-Vista Windows since vCenter server 6.7, please find details in Guest OS Customization Support Matrix.