I can see the dvd/cd drive but it will not play anything.when I click the drive it keeps asking to insert a disk when I have already put one in?

Make sure that the dvd burner is getting enough power test all leads that are attached to the dvd burner including electical extensions and make sure they have a secure connection or just replace them there might be bad/faulty or
your drivers may have been corrupted or you might have a virus run your antivrus program
you might have to physically unplug the leads for this cd/dvd burner then plug them back in or
you might have to uninstall then reinstall your DVD/CD or uninstall the driver then reinstall for this device
control panel admistrive tools,computer management,device manager scroll down cd dvd rom drives right click you can you can update driver,roll back driver,or select properties general troubleshoot, select driver click to reinstall drivers click update driver or uninstall then reinstall

hope this helps