You need to include the file disk1 into this copy. This file is required to be in the $winnt$.~ls directory, so that Windows will find things.
[Files] ;... d1,disk1 ;.....
There are five files that someone is attempting to put into the dllcache, however it does not work this way.
You need to remove or comment any line that contains the string ",44" (ie comma, 4, 4)
[SourceDisksFiles] dmdiag.exe = 1,,,,,,,3,0,0 dmdiag.exe = 1,,,,,,,44,0,0 <--- delete this line