A new KB article (2871131) in regards to an increasing KEY_USERS\.DEFAULT key related to printer settings never being deleted in the DevModes2 key. I’ve seen this issue in several environments, but there is a fix now!
“…Assume that you have a server that is running Windows Server 2008 R2 Service Pack 1 (SP1). Many users connect to the server by using a certain remote desktop application. In this situation, the size of the following registry hive may exceed the limit: KEY_USERS\.DEFAULT
Therefore, the users cannot connect to the server.
This issue occurs because of an error that occurs in the Print Spooler modules. When a user establishes a new remote desktop session to the server, the printer settings of the user are written in the following registry subkey: HKEY_USERS\.DEFAULT\Printers\DevModes2
However, the printer settings are never deleted. Therefore, the size of the following registry hive becomes larger and larger, and various problems are caused by this behavior: HKEY_USERS\.DEFAULT…”
Source & download: http://support.microsoft.com/kb/2871131/en-us?sd=rss