Hi,
How do you know it need IRM to open? Could you let us know the exact prompt message?
According to your descriptio, this document might be protected by IRM. It also might be restricted by user permission.
If permissison for a file has been restricted by using IRM, the access and usage restrictions are enforced regardless of where the information is, because the permisson to a file is stored in the document file itself.
What's the version of your Word? What's your operating system? Is this document created by yourself?
Meanwhile, you could refer to the following articles:
Information Rights Management in Office 2010
http://office.microsoft.com/en-in/word-help/information-rights-management-in-office-2010-HA010354260.aspx
Troubleshoot "access denied" when opening files or folders
http://windows.microsoft.com/en-in/windows-vista/troubleshoot-access-denied-when-opening-files-or-folders
Karen Hu
TechNet Community Support
