[MOSS/WSSv3] Error "Unable to get the private bytes memory limit for the W3WP process."

[ISSUE]
On the environment of a customer we encountered a lot of errors in the event log, which also caused some performance issues. The message was:
"Unable to get the private bytes memory limit for the W3WP process. The ASP.NET cache will be unable to limit its memory use, which may lead to a process restart. Error 0x80070005".

[CAUSE]
The message is caused by a known issue with insufficient permissions in your IIS metabase. The metabase ACL's on the target server did not include the IIS_WPG group on the following two nodes of the metabase (IIS_WPG is in both ACL's on a clean install):
- W3SVC/AppPools
- W3SVC/Filters

[SOLUTION]
Download the MetaACL utility from KB267904. When you have downloaded and installed the program, run the vbs via the following command:

cscript metaacl.vbs IIS://Localhost/W3SVC/AppPools IIS_WPG RE

The path is case sensitive - type exactly as above; after you run this command restart the IIS services and see if this corrects the problem.

Source