Can't find the problem of DVD drive in win7

There are more and more users using Windows 7 system, of course, everyone will encounter various problems in the process of using win7. A common problem with Win7 is that the system prompts that the DVD drive cannot be found. The DVD drive is not recognized by the system. In the device manager, it is just an exclamation mark. The data signature has a problem: "Windows cannot verify the data signature of this device ……" Code52)”
To completely solve the win7 system prompt DVD driver can not find the problem that the DVD drive is not recognized by Windows 7, refer to the following methods.
Method 1:
1. Enter regedit in the start menu and press Enter. Open the Registry Editor
2. Expand the following registration key
HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlClass{4D36E965-E325-11CE-BFC1-08002BE10318}
3. In the right panel, right-click UpperFilters and click Delete
4. Click “yes confirm the value to delete
5. Also delete the LowerFilters value. Confirm Delete
6. Exit the Registry Editor and restart
Tip: When you delete the above two values, you may lose some features, such as CD recorder. If this happens, you must reinstall the affected program. If the problem persists, you may need to contact the program vendor to see if there is an updated version of this program.
Method 2:
1. Click Start->All Programs->Accessories
2. Right-click Command Prompt-> “Run as Administrator”
3. Paste The following command and enter:
bcdedit /set loadoptions DDISABLE_INTEGRITY_CHECKS