Can you identify the source of the "Network Manager" application?
Is it part of the Alienware Command Center?
Is it a product of the software driver package for the installed network adapater(s)
Is it a product of your wireless router software package that you might have installed.
In other words where did it come from? It's not part of Windows 7, nor can I find any mention of it on the Dell Alienware Forums.
Have you tried using your Service Tag Number on Dell Support to see if there are any additional software packages that may be included as part of your PC's software or utilities?
Are you receiving any error messages related to the missing software or any Event Viewer notifications in Windows Logs->Applications or System?
Does the system work OK if you plug in the wired adapter, if that is an option?