Dvd burning question

Assuming I have a dvd that was dual-layered or whatever its called and is like 7gb when copied onto computer as disc image file, is it possible to burn this onto a normal blank dvd disc? If not then is it possible to reduce the image size or extract...

media from it, and make that smaller? How would one go about doing either of these?

I'm not entirely sure,because Im pretty much clueless at this stuff,but I think youd need a file converter,which would also decrease it's size.

thats a HUGE file! I mean normally I can download something massive and it's still half the size...I downloaded all of doctor who series 4, thats 13 episodes at 45 minutes each, and it still only came to 4.7GB!!!

you need to compress it, try a winRaR file... and you don't need to burn the mage into the disc only on it, don't you?

but if it's a series like mine was, then just divide it and do it on two discs...what was it anyway?

(FYI; for the benefit of those that may think I illegally downloaded, I didn't. downloading doctor who isn't illegal, as long as it's off the BBC website... )

It wasn't downloaded lol!!! And I can honestly say that! Instead it was just put on my computer mysteriously... hmmm...

It's the DVD of The Devils' Rejects, full dvd with extras etc. I just want the movie extracted from the ISO and made smaller. I don't care about the extras. Downloading at dial-up speed... no thanks!!! I dunno how to extract media and make it smaller though...