front cover of the new DVD-RW, and then install the old one back, it would not hold up you to use it still.
3): According to experience, all laptop DVD-ROMs are of the same thickness standard: 12.7mm, basically, of the same physical size. But there’re also some super thin DVD-ROMs, which are accorded with some special laptops. But the technical indexes have some differences, and it’s the key whether BIOS could recognize DVD-RW drive or not. If the technical indexes are same, on most laptops, it would not be a problem at all, but for some old laptops, as originally DVD-RW drive hasn’t been ever used, and now if want to update, then compatibility match would be the key of the problem. No matter how, try several times, generally speaking, you can find the DVD-RW compatible with our laptop. Under this circumstance, use the DVD-RW of the same manufacturer (DELL), it’s quite possible to succeed. Hope this could help you!