Using Windows XP, I have tried to burn data onto a cd without success?

Using Windows XP on my Time computer (purchased last year), I have tried, for the first time, to burn data onto a cd and an error message comes up saying The disk is write-protected. Remove the write-protection or use another disk. The disks are brand new and I have successfully used them on my old computer and using Nero (this software is not necessary, apparently, using Windows XP.) Any suggestions?