I have six machines that were imaged via PXE and WinPE and the image was prepared with sysprep.
For some reason they are all using the same GUID and as the Sym Agent on each machine attempts to do an update configuration it re-registers the GUIDs and "rotates" to the current device name in the SMP Console that is associated with the GUID in the database. I have tried to place this GUID in the "itemtodelete" table and in the "agentblacklist" table then manually removed the agent and resinstalled it on several of the machines, and the GUID is always reassigned to it. I too used the /RESET GUID switch and this also didn't resolve the issue. Not all machines that were created with this image are having this issue.
ITMS 8.x
The following Powershell script resolved this issue on all machines (all remotely running elevated powershell):
Enter-PSSession -ComputerName {COMPUTERNAME}
Stop-Service -Name AeXNSClient
reg query"HKLM\SOFTWARE\Altiris\Altiris Agent” – check for “DsUniqueId” value and delete if there (none were present)
dir C:\Windows – check for AeXNSAgent.ini file
del c:\windows\aexnsagent.ini – (if present, and it was on all of these machines)
dir C:\Windows – make sure ini file is not present
cd'\Program Files\Altiris\Altiris Agent'
. .\aexagentutil.exe /resetguid
reg query"HKLM\SOFTWARE\Altiris\Altiris Agent" – make sure key now was “MachinePreviousGuid” to indicate will reset upon agent start
Start-Service -Name AeXNSClient
"Client Machines are sending same UniqueID during Basic Inventory" (KB 210118)