when i try to burn a cd in media player it tells me no cd or dvd burner has been detected press f5 to refresh player -when i do that nothing happens -also i know the burner is working fine because when i use nero express everything works ok

You can try the following:
Copy the files wherever you want them, then go to Windows Media Player and delete everything from the Media Library (it won't actually delete the files, it'll just delete the info on the media player), then go to tools and click on Search For Media Files, it will find every media file in your system and add it to the media library...
I have had issue in past with Windows Media Player 10. What version are you using?
You should generally not use Media Player for burning CDs. Nero is a great software for this.

I think WMP uses the imapi cd burning com service for burning. You have to activate it in the services:
%SystemRoot%\system32\services.msc /s

The problem is also that the imapi cd burning engine belongs to Roxio and is licensed by Microsoft. Meaning, if you install Roxio products and install Directcd included for example with easy cd creator or winoncd it will overwrite the original files and screw the entire imapi service. If you uninstall directcd, imapi service will be gone too. If imapi is gone, windows components (windows explorer, WMP) won't recognize your cdrw drives. Even if you force them to recognize them by hacking the registry, they will still refuse to burn, because the imapi files are missing. Nero and Roxio and whatever else of course still work, but they use their own drivers, so that's a different matter.

So try to activate the imapi service in the services. If it doesn't work - try to reinstall directcd, maybe it will reactivate the imapi service