Hi Pleasessssssssssss Help!!!!!

I tried to burn DVD maker many times but it is not working. I edit a simple video clip from my camcorder to window movie maker and also tried with DVD maker, they are working fine but when i tried to burn them using DVD maker it shows error messages that i don't have enough space on the dise when file only about 100 MB burn into 4.7 GB dise. also sometimes I burn them to dise but dise cannot play in the any DVD or Computer. DVD and computer tell me that there is no dise!!!!

I am using Vista. please e-mail if you can help

thanks