Something similar happened to me...

The WMC Installation completed without error.  But when I tried to run it
(from Control Panel), I got the following error...
---------------------------
Services Dialog Box:
Could not start the Windows Media Connect Service service on Local Computer.
Error 1068: The dependency service or group failed to start.  
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Note: The Administrative Tool, Event Viewer, indicates;  "The Windows Media
Connect Service service depends on the Universal Plug and Play Device Host
service which failed to start because of the following error:
The service cannot be started, either because it is disabled or because it
has no enabled devices associated with it."

So, Install the UPnP user interface...
Open Add or Remove Programs in Control Panel.
Click Add/Remove Windows Components.
In the Components list, select the Networking Services check box, and then
click Details.
Make sure the UPnP User Interface check box is selected.

Notes
To open Add or Remove Programs, click Start, click Control Panel, and then
double-click Add or Remove Programs.
If you used a CD to set up Windows, you will be prompted to insert it into
your computer.

Note: For me, the installation completed successfully.  

---------------------------

Next Problem: The UPnP Service is not started, and would not manually start
due to a dependency on SSDP (Discovery Protocol), which guess what; is in the
disabled state.  

So, both SSDP and UPnP need to be started.  

What I did (first attempt) was to set the startup type for both to Manual
and then manually start SSDP followed by UPnP.  

Now, I can now run WMC, find my media rendering device (Roku HD1000), etc.  
I haven't tried to do much with it (yet).  

My next effort will be to set the startup type for both SSDP and UPnP to
Auto and then reboot the system.  

Note: The steps to Start SSDP and UPnP...

Log on to your computer as an administrator.
Click Start, and then click Run.
In the Run box, type services.msc.

Right Click on SSDP Discovery Service and Select Properties
Under Startup Type set to either Manual or Automatic (???)  (I've tried only
Manual)

Right Click on UPNP Device Host and Select Properties
Under Startup Type set to either Manual or Automatic (???)  (I've tried only
Manual)

Right Click on SSDP Discovery Service and Select Properties
Select Start

Right Click on UPNP Device Host and Select Properties
Select Start

I hope this helps.  Please keep the discussion going.