If you want to perform completely unattended imaging, you need to change the computer so that it boots from the network when there is an imaging task. There are two ways you can do this:
- You can change the boot device order so that a network boot is tried first. This is changed in the BIOS setup.
- You can leave the boot order as it is but, when required, edit the boot configuration of the hard disk so there is no bootable partition. Then the boot sequence will fail through to the network.
Change the BIOS
Normally when the computer boots there is a BIOS option F12 to break out of the boot sequence and perform a network boot. The computer then looks for a PXE server on the network to download an OS into RAM disk and boot from that. Obviously you have to be at the computer to press the F12 key.
However if you press F2 to enter the BIOS setup you can change the boot device order to put the network boot first. When this is done, the computer will always first attempt a network boot. It will register itself with a PXE server and download a boot loader. This only takes a few seconds. The computer is then under the control of the boot loader program and can be told what to do next. It can:
- Wait a few seconds for user input before continuing with a normal hard disk boot
- Automatically proceed to download and boot from a boot image.
Being under the control of the PXE server provides the opportunity to automate the imaging task. However you need a server deployment tool that can make use of this. WDS and MDT do not do this.
To change the boot order you need to visit the computer. But if you are going to visit the computer you may as well do it when you re-image. And then you have no further need to change the boot order. So changing the boot order is really only relevant if you want to be able to perform unattended imaging of clients in the future. There are two ways you can set the boot order remotely.
You can push out a BIOS update to the computers. If the computers are one or two years old this may not be a bad idea. You can use the vendor’s tools to do this.
Here is an example of the HP BIOS update tools provided by Altiris.
And the equivalent for Dell.
Or you can use Intel vPro. The Active Management Technology (AMT) feature enables you to create a security context between computers at the BIOS or firmware level. Once this security context is created you can use it to manipulate the BIOS remotely. AMT is a seriously heavyweight feature that enables secure management of the computer before the OS is booted, "Out of Band". You can power on, take an inventory (e.g recognise which computer it is) and perform operations on the disk without booting. To do this you need an AMT Management tool.
Change the Boot Configuration
In Windows 7 the Boot Configuration is stored in the Boot Configuration Data Store. It is edited with BCDEdit. For fully automated imaging your deployment server can edit the boot configuration and then restart the computer to boot into an imaging task.