start /b "" "c:\Program Files\Oracle\VirtualBox\VBoxHeadless.exe" -startvm "debian604 64"
If you read the parameter list with
START ["title"] [/D path] [/I] [/MIN] [/MAX] [/SEPARATE | /SHARED]
[/LOW | /NORMAL | /HIGH | /REALTIME | /ABOVENORMAL | /BELOWNORMAL]
[/NODE <NUMA node>] [/AFFINITY <hex affinity mask>] [/WAIT] [/B]
"title" Title to display in window title bar.
If it is an internal cmd command or a batch file then
the command processor is run with the /K switch to cmd.exe.
This means that the window will remain after the command
has been run.
If it is not an internal cmd command or batch file then
it is a program and will run as either a windowed application
or a console application.
parameters These are the parameters passed to the command/program.
It expects a
title enclosed in quotes (
"). Since your program path included quotes, it got interpreted as the title. Adding an explicit title (in this case, empty,
An alternative method is using the
/d switch to specify the path. Specifically:
start /b /d "c:\Program Files\Oracle\VirtualBox\" VBoxHeadless.exe -startvm "debian604 64"
It appears to take the first argument after the
/d switch as the path, even if it is quoted, and if the next argument is not quoted then this works. Everything after what is recognised as the command/program is passed as a parameter to that command/program. Note this will not work if the command/program has spaces in the name, e.g.
VBox Headless.exe, since that would require quotes and be recognised as a title.
Overall, the first (explicit title) method is probably better. It was a bad design choice on the part of Microsoft, they really should have added a switch for title rather than "is the first argument enclosed in quotes?".