One of the classic error I always get since windows 7 release is "A CD/DVD drive device driver is missing". If you have a driver floppy disk,CD,DVD or USB Flash Drive, please insert it now.
Solution: Disable USB 3.0 on BIOS -Enter BIOS and look for USB 3.0 setting. -Select Disable or if disable option is not available select Auto.
IF you are using DVD to Install Windows 7 This error pop-out