Hi Luc,
Rather than running the batch this seems to work.
Invoke-VMScript -VM VM1 -ScriptText "C:\SQLIO\SQLIO.EXE -s120 -kR -frandom -b4 -t4 -o32 -LS -BH e:\Testfile.dat" -GuestUser administrator -GuestPassword password
Can you help me with having this executed simultaneously on multiple guest VMs ?