Memory limit for the W3WP process

Hi
I have a window servere 2003 enterprises edition and i have installed iis on
the same machine. I memory of that server is 16gb But if i check in the task
manager its always show using 2.7 gb of ram(memory) this means i have enogh
extramemory on my server. But I still receiving an error which is as follows.
"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"
So please have a look this error and help me to solve this issue.
Thanks


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Atul