When booting the client into WinPE, the client states:
Info: The boot selection failed because a required device is inaccessible.
1. Corrupted WinPE files or installation.
2. Network packets are flooding and/or dropping.
1. First, verify that the MTFTP service is running, and that the PXE Server and MTFTP services are set to manual. This could help prevent conflicts between services. Restart the PXE Config Helper service, which should restart the other three services in the correct order. Test your job at this point.
2. Create a new WinPE configuration from the PXE Config Utilty. Set the job to use the new WInPE configuration and test.
3. Delete the part of the x86 directory created by Bootdisk Creator - not the whole thing (part of this folder is only created on installation, so to get some of the files back, you will need to run DSSetup). You may also want to clear out parts of the x64 and IA64 directories. These are located under ...\Program Files\Altiris\eXpress\Deployment Server\Bootwiz\platforms\WinPE2\x86. You should leave the following folders that are installed with the product prior to installing WinPE:
4. Delete all contents in WAIK folder in the eXpress share.
5. Reinstall WinPE files with the PXE Configuration utility by creating a new PXE configuration and clicking the "Add pre-boot" button. After creating a new WinPE configuration and letting the PXE Configuration utility save the new configuration to the PXE server, check ...\Program Files\Altiris\eXpress\Deployment Server\PXE\Images\MenuOptionNNN\X86PC\sources to verify that the boot.wim file exists with a new modification date.
6. Run a network trace (WireShark for example) to evaluate network packet traffic and identify problem sources.
7. Does the client computer have at least 512 Meg of RAM?
Also refer to Article: TECH40825 for related issue and solution.
Deployment Solution 6.9