You may receive a "Windows could not start due to an error while booting from a RAMDISK" error when trying to use ADS 1.1 to boot Deployment Agent

Source: Microsoft Support

RAPID PUBLISHING ARTICLES PROVIDE INFORMATION DIRECTLY FROM WITHIN THE MICROSOFT SUPPORT ORGANIZATION. THE INFORMATION CONTAINED HEREIN IS CREATED IN RESPONSE TO EMERGING OR UNIQUE TOPICS, OR IS INTENDED SUPPLEMENT OTHER KNOWLEDGE BASE INFORMATION.

If you are experiencing issues booting to the Deployment Agent (DA) on recent hardware, you may be encountering an issue where internally the target machine is listing more than 88 devices. In this scenario, when�you try to boot to the Automated Deployment Services (ADS) using boot-from-DA you may get�the following�error message:��

"Windows could not start due to an error while booting from a RAMDISK. Windows failed to build a bootable Ramdisk image. Rebooting in 5 Seconds" while attempting to boot

If you turn on ADS trace logging you will not see any conclusive evidence of any failures as this particular message is generated early in the DA creation cycle.

This is a known issue in ADS 1.1

You can either remove some of the devices that will be included in the 88 devices, or use a�WinPE 1.6 image to boot to.

Please contact Microsoft Technical Support for information concerning WinPE 1.6 availability and reference this article.

When a target system PXE boots, ADS sends down some code to enumerate the devices on the system. This list of devices is sent back to the ADS controller so that the controller can build an ADS Deployment Agent containing the right set of device drivers.

The device enumeration is done using NTLDR with an enhancement to send the device list back to the ADS controller over the network. This enhancement uses BIOS calls to send a UDP packet. We limit the size of the UDP packet to the underlying Ethernet frame size. In a typical configuration, this means there is room for 88 devices in the UDP packet. If the target machine returns greater than 88 devices, overflows the UDP packet, and DA fails to be created.

The NTLDR pulls the list of devices from the target machine system BIOS. �Please review the following articles on how PCI devices are detected and for more information on identifiers.

�

How PCI Devices Are Detected and Why They May Fail

http://support.microsoft.com/kb/170922/

�

Identifiers for PCI Devices

http://msdn.microsoft.com/en-us/library/ms791082.aspx

�

To take a look at the list of devices on a target machine take a look at the following link:

The DevCon command-line utility functions as an alternative to Device Manager

http://support.microsoft.com/kb/311272

�

�