This is either due to a lack of network drivers, or due to the drive mapping command, net use, executing too early in the boot sequence.
First, you must verify that you have networking capabilities in the boot environment. To do this, boot with your existing Windows PE boot disk , then choose Quit to exit Ghost. At the command prompt, type the following, then click Enter:
If an IP address is present, and is not 169.xxx.xxx.xxx, then you have networking capabilities. If this is not the case, you will need to add the appropriate network driver according to these instructions:
How to add drivers to DeployAnywhere or WinPE.
If you have networking capabilities but still cannot map a drive, it is likely that the net use command is executing too quickly. To resolve...