Some of the controls on this property sheet are disabled

"Some of the controls on this property sheet are disabled because one or more other Network property sheets are already open. To use these controls, close all these property sheets and then reopen this one"
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Steps to reproduce:

1. Open “network connections” from the control panel.
2. Right click on “Local Area Connection” and click “properties”

Resolution:

1. Download drivers for your current network card.
2. Uninstall all your network cards from (Control panel->System->Device manager)
3. Restart your computer.
4. Let windows attempt to install your network card for you. If windows can not find the correct network card drivers use the one you downloaded in step 1.

If you are still having problems you could try;

• Uninstall all network related applications, eg HP wireless assistant, HP wlan assistant, ect…
• Uninstall all virtual machine applications, eg VMWare, Virtual box, ect…

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Are you opening the Local Area Connection so the Status Window is open? or just Right clicking the Local Area Connection? Are you logged in as a limited user or as an Administrator user? Enable the Hidden Administrator account and log out of the user profile your in and log in as Admin and see if it works there. then check your user account for restrictions. 
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Try this: http://www.chicagotech.net/netforums...t=3921&start=

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Based on my research, the issue is usually caused by an aborted NIC driver
installation process which leaves a registry value under the following key:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce
I suggest you try the following steps to delete the registry value:
1. Click Start, type regedit in the Start Search box and press Enter.
2. Navigate to the following key:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce
3. Right click RunOnce and select Export to make a backup.
4. In the right pane, delete the value referenced to rundll32.
5. Quit Registry Editor.
Then, restart the computer to test the issue.
If the issue persists, please reinstall the NIC driver to check the result.
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Here's what happened, if you want to know. When I attempted to set the NetBEUI protocol up McAfee Firewall locked me out. I did not know you had setup McAfee to allow different protocols. This is an off the shelf version and all other devices use Enterprise version. ANYWAY, I knew the install was not complete so I searched the registry for "install" and found 3 items 2 were queues in waiting and the other was in HKLM, software, MS, windows, current version, runonce. Deleted that, rebooted and voila! I was back in control.