As the file manager application in Windows, I suspect Explorer was written not to allow multiple copies of itself and that all requests would attach to the single running instance.
I may have been a tad
wrong misguided with my suspicions.
Starting explorer with
start /wait or inline results in
two copies of
explorer running. However, the batch file continues to wait for explorer to end.
Interesting to note:
Batch file copy: high priority using 20 MB
System copy: normal priority using 35MB
Normally
explorer lives in the Windows directory. Any chance there is another copy in your path? Just asking.
My copy of explorer is dated 4/14/2008 and seems to work as advertised. This gets curiouser and curiouser!