I always used several commands in one line using just one "&", but all references I can find online using two "&" - so "&&" ...
here is what i mean :
C:\>net stop "DNS Server" & net start "DNS Server"
The DNS Server service is stopping.
The DNS Server service was stopped successfully.
The DNS Server service is starting.
The DNS Server service was started successfully.
C:\>net stop "DNS Server" && net start "DNS Server"
The DNS Server service is stopping.
The DNS Server service was stopped successfully.
The DNS Server service is starting.
The DNS Server service was started successfully.
So it doesn't seem to make a difference .. or does it ?