Help Please (Virtual Dub)

[kurz]

I got an AVI file and I converted it to MPG file. When I went to burn it it says disk is not big enough. The file is 1.2 gig after converting it to MPG file.
Is there a way to split the file so I can burn it?
I was reading some of the messages and some said to use Virtual Dub,I don't know if I'm Dumb or what, but I can't figure out the program to split the file