Why/how is svchost.exe using 6.5GB of memory?
Solution 1:
svchost.exe is the process that runs all your Windows services. One of them has gone mad apparently. Right-click on svchost.exe and select "Go to Service(s)". That will tell you which service it is, and you can use Services Manager to restart or disable it if you don't need it.
For a better description with nice screenshots check out:
- How-To Geek: What is svchost.exe And Why Is It Running?
Per your update, you can check out a couple of those services:
- CscService: Related to the "offline folders" feature of Windows. Do you use that?
- UxSms: Related to Desktop Window Manager. Try disabling Aero, see if the problem occurs.
Solution 2:
After splitting suspected services to separate processes I was able to identify Network Store Interface Service (nsi) to be the cause of memory leak in my case (Windows 7).
There is ten-page thread about this issue at http://answers.microsoft.com/en-us/windows/forum/windows_7-system/nsi-memory-leaks-fixed-yet/f3c3e9db-36a7-45df-9dbd-de9455378498.
It mentions a couple of hotfixes available for download on demand:
http://support.microsoft.com/kb/2847346/en-us
http://support.microsoft.com/kb/2950358/en-us
There is also a similar fix for Vista and Server 2008:
http://support.microsoft.com/kb/2743187/EN-US
Solution 3:
Another option: Use Process Explorer.
It can be downloaded via Microsoft TechNet.
It displays all running processes, you can easily see which svchost.exe is using CPU or RAM resources, to track down which service is runnning wild.
Tip:
When hovering the mouse cursor over the 'svchost.exe' entries, all services associated with this process are listed in an infotip window.
Alternatively, select the process, click "Properties" and choose the "Services" tab.
Solution 4:
This happens after updating to Windows 7 Service Pack 1. Memory leaks can happen when the background service for Windows Update (netsvcs) is enabled. You can find more info here, among other places. See Awa's answer here to verify that Windows Update is at fault.
One inelegant solution to this issue is to turn off Windows Update and install all updates manually. Run services.msc and set Windows Update and Background Intelligent Transfer Service to Disabled. See here for general instructions on services.
However, several updates to fix this issue have been rolled out by Microsoft. When you first run Windows Update in a new installation of Win7 SP1, it will insist on installing Windows Update Agent [WUA] 7.6.7600.320 (KB2887535), before it lets you check for other updates. Let it do so or apply the update manually if installing offline. After doing so, you might not be able to install other updates automatically until this issue is resolved.
Then, manually download and install the following update:
https://support.microsoft.com/en-us/kb/3083324
This updates the Windows Update Agent to version 7.6.7601.18979.
This is the newest update in a series released by Microsoft to address the issue. Each has been replaced by a newer version, and it seems that you only need to install the newest one. However, if this does not fix the issue, you can try installing an older update in the series, or perhaps install them all sequentially. In chronological order, consult the following updates:
https://support.microsoft.com/en-us/kb/2990214
https://support.microsoft.com/en-us/kb/3050265 (June 2015)
https://support.microsoft.com/en-us/kb/3065987 (July 2015)
https://support.microsoft.com/en-us/kb/3075851 (August 2015)
https://support.microsoft.com/en-us/kb/3083324 (September 2015)
Then, according to this answer, install this update:
https://support.microsoft.com/en-us/kb/3102810 (20-Oct-2015)
This updates the WUA to version 7.6.7601.19046. Theoretically, you should be able to just skip to this step and be fine. However, this update claims to not replace earlier updates, which is why it might be advisable to install the aforementioned update(s) first.
Lastly, it might be advisable to disable the two aforementioned services before manually installing these updates, then re-enable them afterwards. I think you should be fine either way, though you might want to restart your machine after each update, just to be sure.
Reports vary, but this should fix your troubles with Windows Update hogging memory and CPU :)