Pioneer dvd rw dvr 111d isn't burning properly

I have a Pioneer dvd rw dvr 111d that's not working right. I use roxio easy cd/dvd creator 6 for burning movies. It only burns them only about 1.2x-1.5x and suppose to burn up to 16x. I've been using roxio with this burner for a long time with no problem. A month or so I had a problem with the sound(soundcard) and couldn't fix it so ended up reinstalling Windows XP. That fit the sound problem. I installed Roxio and it work for a time or two. Then one time I tried disc copier in Roxio it said no supported recorder was found. If this keeps happening to reinstall Roxio. Which I have Several times and a few times it would come up with that message and would work properly. Then I would shut down cpu and I rstart it and use Roxio it would come up with the no supported recorder message. Also when I start itunes it pops up a message saying the registry setting used by itunes drivers for importing and burning cd and dvd are missing. This can happen as a result of installing other cd burning software. Please reinstall itunes. I install itunes right before I started having this problem, I think. I haven't tried to reinstall itunes yet because I hate to lose my data. Is there a way you can save the data and uninstall and reinstall itunes? Does anyone know if itunes has anything to do with my dvd burning problems? Thanks