Vimarun install a windows service on your behalf.
During installation you are asked for your user credentials, this is so that the VM can run under your user account.
The Windows service runs under your account and will start/suspend the virtual machine(s) for you.
This also means that the VM gets the same privileges as you normally do. The restrictions that used to be applied for VMware Shared Virtual Machines ( http://kb.vmware.com/kb/2005585 ) do not apply here, because we are running the VM in this way.
When the VM starts with the host it will always start in background mode. There is no desktop before the user logs in and you cannot start a VM in foreground mode without a desktop.
If you have configured your virtual machine to run in foreground then immediately after you log in, the virtual machine will switch from background mode to foreground mode. This switch from background to foreground can give a bit of a hickup while using a VM remotely and if that is your game then you might prefer to keep running the VM in the background.
Once it is time for the host to shut down, it will ask each process if it is OK to shut down. Windows by default gives each process 20 seconds to shut down. As such we try to suspend your VM(s) as quickly as possible, the moment Windows sends this notification.