Things to be Checked :
1. Try to manually copy the image file from the Image share to different location.
2. Check the transfer Speed or Copying speed and then can be determined if its issue with network in general.
3. Check if there is any Layer 3 Device as Switch or Router between the DS server and Clients where we are deploying the image.
a. Most of the times it’s the Quality of Service (QoS) configuration for the port priority based transmission of the data.
Frames received from users in the administratively-defined VLANs are classified or tagged for transmission to other devices. Based on rules that you define, a unique identifier (the tag) is inserted in each frame header before it is forwarded. The tag is examined and understood by each device before any broadcasts or transmissions to other switches, routers, or end stations. When the frame reaches the last switch or router, the tag is removed before the frame is sent to the target end station. VLANs that are assigned on trunk or access ports without identification or a tag are called native or untagged frames
Other things to check :
1. If there is an old driver which is existing in the boot image and even if there is a new driver it takes precedence , so delete the old driver from : \eXpress\Deployment Server\Bootwiz\platforms\Winpe2\x86\Drivers.
2. Disable the Chimney Offloads on the NIC on the servers by using :
a. Right-click on Network properties/places.
b. Right-click on the Local Area Connection and select Properties.
c. Select Configure.
d. Select the Advanced tab.
3. Remove or alter current SMB throttling settings on layer 3 switches and/or routers.
To verify that SMB throttling is the cause of the issue, the following test will verify this issue:
a. Create a Copy File To job that copies all files of a complete image to a directory on a Windows XP workstation. When this job is run, the copy process should take several minutes to complete because SMB is NOT being used in the copy process.
b. From the same Windows XP workstation, establish a network connection to the image file source and "drag copy" all files of the same image to a directory on the hard drive. This process will probably take +30 minutes since this IS using SMB which is being throttled on the network.