...Usually, if a DVD drive only plays CDs it means that a) there is a driver issue or b) ther is a problem with the DVD laser. These composite drives can usually do both jobs by using a laser lens for CD and a different one for DVD. The DVD one may be faulty.
You usually don't delete files from CD or DVD disks. Certainly don't try to format CD R or DVD R disks! They're ready to go!
Despite what Device manager says, I think it may be a faulty drive and would return it on warranty.
You usually don't need an installation disk. Windows provides drivers.