Does it only fail to read cd's,dvd's or both?
The lasers don't tend to last long with these writers, sometimes only 8 or 9 months depending on usage. Mainly because they are cheap and cheerful and aren't dear to replace.
You could try going into device manager via control panel > system > hardware and clicking on the + sign next to DVD rom drives.
Then right click your DVD drive and choose uninstall. Then reboot your PC and it will reinstall it automatically which sometimes works.