I tried to copy CD through windows media player onto my pc, then use my r/w to copy it onto a blank CD-RW disc. It says that it copied succesfully but it won't play on my home stereo or car stereo. It says there is no disc in there.
Some hifis and car stereos can read CDRW but theres very few of them that will. Stereos that can read MP3s as well as normal music cds are probably more common but they tend to be much more expensive. There is nothing wrong with your stereos its just that they won't read CDRW as the others have said you'll need to use CDR. Even then there are a few stereos which won't read recordable cds at all. I suggest you try it and see.
It depends, as I said above some (and by some I mean very few) stereos will not read a CDR. Of all the people I know there is only one who can't play cdrs at all so go and try it the chances are 99.9% that it'll work. By the way I wouldn't take the word of someone in PC World if he told me the sky was blue, I'd have to check for myself. The only time I did speak to someone from PC World he tried to convince me that AMD processors wouldn't run a lot of Windows programs which as everyone knows is rot. (He was trying to sell me an expensive Intel based system at the time)