Can I get some help with my new DVD burner


I got an external computer DVD burner for Christmas but I'm having some serious trouble with it and I'm beginning to get frustrated. The burner is made by Memorex and its model # is: MRX-530LE.
I had some old home video that my parents wanted me to burn for them so I uploaded it to my hard drive and edited it and converted it to MPEG format. When I began burning I tried to use as much of the disk as possible so I ended up having 4.2 GB out of the 4.38 GBs on the disk. I began the burn processes using Nero 7 Essentials (which I also used to edit the video). After about 6 hrs of burning the disk popped out and a message came up saying that a critical error had occurred in the Burn process.
So I took out the disk, and reinstalled all the software it came with because I thought I might try out the lightscribe feature in the Burner. I went to the place in the software that makes light scribe labels and made the design. But when I went to print it onto the disk, there was only an option to print to standard printer paper. I turned the Burner off and unplugged it from the computer and plugged it back in. I went into the software preferences to where it says something like "Lightsribe Drive:" and I tried to select the drive but it was not showing up in the drop down box. So I went into control panel and selected "add new hardware" and I clicked where it showed the memorex dvd drive. I went through the steps and it finally ended up saying "This device is working properly."

So in summary I need help knowing if it is my computer that is messing this up, the DVD burner thats malfunctioning, or the Software it came with it.

Any suggestions would be greatly appreciated.