MPI error based on host order

I'm setting up new MPI environment with two windows 8 pc. 

Running the command below in ether order works on both machines.

mpiexec -n 1 -host machine1 hostname : -n 1 -host machine2 hostname

Then running the next command below works depending on the order. test.exe is in a newly created folder on the C drive of each machine.

mpiexec -n 1 -host machine1 test.exe : -n 1 -host machine2 test.exe

When listing machine1 first and machine2 second and running the command works on either machine. Then when the hosts list is reversed the command fails on on both machines with the following error.

Thanks in advance