When I run iTunes diagnostics, I keep getting the same message, no audio cd found, even if I have one in there that I know works.

I have not been able to import or burn cd's since August 2012. I have checked my registry settings and most other suggestions I have found in "support". About 1 in 10 attempts at diagnostics will recognize the cd I've inserted for the diagnostics but when I put in a CD-R it does not allow me to burn a playlist or recognize that I have inserted a blank cd. Please help, as I am PC/Mac illiterate and cannot afford to pay someone to fix what was working just fine before August.