On the Start Menu Under all programs find the program Group called Startup.
If you see the VG icon in that group, Right Click on it and Delete it.
That will stop VG from Loading when Windows starts.
Then you would have to Manually click on the Virtuagirl Icon to Load the program each time you want to use it.
Also as Dmon1981 mentioned:
On the Advance settings screen, Make sure Always Start Disabled is checked.
That way if the VG program is Loaded, it will load in the In active ( Black "V" ) state.
And if you place a check mark in the Password box, then it won't play unless you type in the password "striptease"
So the combination of these three things, will prevent accidental displays of the girls on the screen.