Thankyou all for your responses. They are much appreciated.
The reason I asked this question is that a while ago I made a DVD with Vegas and went to play it in Windows Movie Player and remember that the fast forward function was not available. I was not sure at the time whether this was attributable to Vegas renders or WMP. I have since read that some formats eg AVI can cause this to happen in WMP. I just thought someone might have figured out a way to force this to happen. For my purposes, I wanted to create a safety video whereby the viewer could not skip through the presentation by fast forwarding, therefore having to watch it from start to finish.
I appreciate now that this may not be within the realms of Vegas Pro but you never know until you ask, right?
thanks again
Mark