When ever I try to burn a DVD, my drive tells me to insert a blank disk but I have already inserted a blank disk. I have tried reinserting the disk a number of times but it still doesn't work. I have a Sony pc running XP. I have a DVD R/RW drive. . .

Did the DVD-RW drive and recording software come with your Sony? If not, you might find that the software doesn't support the drive, in which case you may be able to get an update from the software manufacturer's web site.