Here is an example with no cancel button. The 180 is the automatic timeout.
Code:
'vbscript
set WshShell = CreateObject("WScript.Shell")
WshShell.Popup"The imaging process is complete." & vbcrlf & vbcrlf & _
"Remaining Steps:" & vbcrlf & vbcrlf & _
"- Install Office and any additional division specific applications", 180, "Finished", 64
If you actually want them to acknowledge it use this (note no timeout):
Code:
'vbscript blah blah
Dim intClicked
set WshShell = CreateObject("WScript.Shell")
intClicked = WshShell.Popup("Office is going to instal.", ,"READ THIS. . .", 49)
If intClicked = 2 Then
WScript.Quit(2)
End If
Then capture code 2 in the DS job as a Failure with a message like "user cancelled installation"
Research the vbscripts on google. I think you have ample information to start your search.