@Giggsie
As the yahoo thread says, it could be old hardware, unable to read -R discs or it could be the software is from the era before that format came to market.
You could try Start/Control Panel/Device Manager (or Hardware and Sound) and see if you can find the manufacturer and model number of the DVD drive, without having to dismantle the computer. Then google the make, model and the word "specification", to see if anything useful shows up.
However, easiest/cheapest/quickest fixes should be tried first. Disks are so cheap that you should just try burning to a fresh blank disk. It could be surface dirt or a scratch in a crucial place was locking out whatever happens during finalisation.