Device manager blank.

Dont you hate that everyone keeps saying the same thing over and over again and ignore you. I have the same Enum permission denied error. Were you ever able to get it solved?

method 1: my plug-and-play is already at automatic.

method 2: I tried till step "e", after I clicked ok, there's a prompt saying that I do not have the permission to change.

I saw this method somewhere, but when I click 'ok' when i edited the enum, it say I do not have the permission to do it.

I saw this method somewhere, but when I click 'ok' when i edited the enum, it say I do not have the permission to do it.

When you open Device Manager, no devices appear in the list. Instead, a blank window appears.

This behavior occurs if the Plug and Play service is turned off (disabled).

Method 1: To resolve this behavior, set the startup type for Plug and Play to Automatic. To do so, follow these steps:

a.     Click Start, click Run, type services.msc, and then click OK.

b.     Double-click Plug and Play. If you receive a Configuration Manager message, click OK.

c.     In the Startup Type list, click Automatic, and then click OK.

d.     Close Services.

e.     Restart the computer.

Method 2:

The other reason Device Manager may be empty is because there are security issues with the key in the registry.

Note: Serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article: http://windows.microsoft.com/en-US/windows7/Back-up-the-registry   

a.     Click Start-> Run->type in regedit.exe.

b.     Locate the following: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum

c.     Now right-click on Enum and choose Permissions.

d.     Click the Add button and type in Everyone and click OK. Check the Allow box next to Read for Everyone. Now click Add again and type in System. Check the Allow box next to Read and Full Control for System.

e.      Both the check boxes under Allow should be selected when you highlight System. Also be sure to click on the Advanced button after adding both users and selecting Reset permission entries on all child objects with entries shown here that apply to child objects. Click OK.

f.      Restart your computer now and check if the issue persists.

try the following solution from the following thread:

http://answers.microsoft.com/en-us/windows/forum/windows_7-hardware/win-7-device-manager-screen-blank/8bc3b870-fee9-4cc6-98c5-a323e5610ce8