Hi,
Thank you for your post.
Please follow the steps to find out what service is using most of your memory.
1. Right click the taskbar, and click Task Manager to open.
2. In Task Manager, click on the Processes tab, and look for the process that is using abnormal memory usage and note its PID (Process ID).
Note: You may need to go to the "View" -> "Select Columns" menu and check PID (Process Identifier) first.
3. Once you have the PID, please run the following command line from a command prompt:
tasklist /svc
4. Please check the output item of the related System process (with the recorded PID)
Meanwhile, you could read the following document to troubleshoot the process:
Getting Started with SVCHOST.EXE Troubleshooting:
http://blogs.technet.com/b/askperf/archive/2008/01/11/getting-started-with-svchost-exe-troubleshooting.aspx
Best Regards,
James