1. What does the PC do? Does it spit the CD-RW back out, or does it just sit there?
2. A CD-RW must be formatted in order to be used. Have you tried opening your CD burning program and activating its formatting function? Usually that happens automatically when a CD-RW is inserted, but perhaps something's wrong here.
Start with these items and post back.
every time I try to put in a cd-rw my emachine 633 ME (cd-rw compatible)won't accept it. only a cd-r

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic