Way too little info there. dsmondo. What OS Operating System? "Not working" how? Not showing up in Windows Explorer, or errors reading or writing, with what program, or what? Also, I'm curious, what do you mean by "put in two more drives"? Physically, or added references in the Windows Registry?
Anyway, try Microsoft.com through IE Internet Explorer:http://support.microsoft.com/gp/cd_dvd_drive_problems
Tell us more, and let us know how this plays out.
Peter Blaise dot com