Solved svchost.exe High CPU Usage in Windows 7 Caused by UPnP Device Host Service

To begin we need to look at what this service is actually for to better understand the cause in this case for the high CPU usage.

Universal Plug and Play (UPnP) is a set of networking protocols that permits networked devices, such as personal computers, printers, Internet gateways, Wi-Fi access points and mobile devices to seamlessly discover each other's presence on the network and establish functional network services for data sharing, communications, and entertainment. UPnP is intended primarily for residential networks without enterprise-class devices.

For more information about UPnP the original source of the above description is quite accurate and can be reviewed http://en.wikipedia.org/wiki/Universal_Plug_and_Play at this website address.

In my case the reason for the high CPU usage was directly related to Internet Connection Sharing (ICS). Having previously shared my USB wireless internet connection with my Local Area Network (LAN) I could temporarily access the internet using another computer on my network, once I was finished I simply disconnected the LAN from my system without giving a second thought to the share I had setup.

After some trouble shooting it appears that whenever I would establish an internet connection using that shared connection my CPU usage would jump to about 30% and would not subside until the connection had been closed. When I looked into the service that was causing this it became clear that while the network adapter the shared connection was bound too was reporting cable unplugged (which it is) the UPnP service would continually attempt to discover devices or allocate a valid IP address on this adaptor thus creating many unnecessary CPU cycles, this is merely speculation on my part though as I have not read all of the documentation regarding the service or reviewed its source code.

In my case simply removing the share on the connection resolved the problem however I would expect having a valid network connection on the adaptor in question would also resolve the problem.

Some may suggest that disabling the service is a solution however it is a useful service in terms of discovering network devices like a Network Attached Storage (NAS) device thus I wrote this to help others identify the cause of this behaviour.

There are other potential causes for this behaviour that are outside the scope of this article should the problem persist then a solution although not ideal is to simply disable the service as mentioned above.

• To stop a service press the Windows Key + R and type into the run window services.msc and press enter.
• Find UPnP within the list of services and right click then click properties.
• There you will see a dropdown box labelled Startup Type: change this to disabled then press ok.
• Restart your computer for the changes to take effect.

And you’re done.