ITFB
Some home and car audio equipment doesn't recognise MP3, so, although you can continue to encode and keep music on your PC in this format, you will need to burn to CDs using a 'lossless' audio format, such as .WAV for the PC, or AIFF for Mac users such as myself.
First of all, check the relevant program menus to see whether Nero will allow you to convert to either of these formats. If you have no luck with that, perhaps one of the PC gurus on here will be able to help you further? Good luck!
Jx