Windows doesn’t recognize CD-ROM drive

When I start my system, BIOS recognizes my DVD drive, and if I put a system disk in, it also shows the driver. When I start windows though, there is no CD listed in the device manager. I have recently downloaded a CD driver which has updated my autoexec.bat and config.sys files so that my CD drive shows, but it doesn’t act like it should. It won’t autorun, it goes really slow if I go through the run screen, and some programs won’t run at all. it was working fine the day before when I had toreinstall windows and used it to reinstall most of my software. Any ideas would be greatly appreciated.