Using boost shared memory. One process creates shared memory ( as an administrator on windows). shared_memory_object(open_or_create, pShareName, read_write); Another process ( not administrator) tries to open and map to shared memory. shared_memory_object(open_only, pShareName, read_write); <-this fails with access denied Check permissions in on file and users only have a read permission. Once those are changes ( after created by the process running as administrator) the file can then be opened and shared by the other process. Is this how shared memory works. I check the code and createfile has a file_share_read|write|delete option and is set to Generic_read|write. I have not been able to find any literature on a solution, but have seen the problem on the net. Thanks Carla Strembicke Software Developer [cid:image9f88f7.jpg@6cbb1949.05f74c72] SUBNET Solutions Inc. www.SUBNET.comhttp://www.subnet.com/ Making Substations More Intelligent T: 403.270.8885 F: 403.270.9631 #100, 4639 Manhattan Road SE, Calgary, Alberta, Canada; T2G 4B3 Follow SUBNET: Twitterhttp://www.subnet.com/subnetsoc-t.htm | Facebookhttp://www.subnet.com/subnetsoc-f.htm | Linkedlnhttp://www.subnet.com/subnetsoc-l.htm Visit the all new SUBNET website at http://www.SUBNET.comhttp://www.subnet.com/ CONFIDENTIAL INFORMATION NOTICE: The information contained in this e-mail is privileged, confidential and intended solely for the use of the addressee named above. If the reader of this e-mail is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this e-mail is strictly prohibited. If you received this in error, please contact the sender and destroy all copies of this e-mail. Thank you.