Occasionally the www publishing service w3wp.exe process causes very high CPU and Memory usage. It can cause the computer to become unusable and freeze. It is a problem on low end Windows servers with single core processors.
KNOWN ISSUE with the 'Garbage Collector'.
Just waiting for the 'Garbage Collector' will not complete its tasks. Assume that this is not a problem for real servers that will run on PCs with several processors.
Restart the 'World Wide Web Publishing Service' (W3SVC)
ITMS 7.1 Sp2
Microsoft Windows Server 2008 R2