Slow saving of Office files to a network server using EFS
If you use the Encrypting File System (EFS) to secure the Temporary Internet Files folder, you will experience slow saving to a server that is capable of supporting encryption but is not configured to do remote encryption. We've had reports of this causing a delay from 45-120 seconds to save a file.
When you save files, the Office applications (Excel, Word & PowerPoint) will create a temporary file in secure subdirectories of the Temporary Internet Files directory, called Content.MSO and Content.Word. If the subfolder is encrypted using EFS, the file that is then copied to the server will have the encrypted attribute applied to it as well. If the server supports encryption but is not configured to do so, multiple attempts to keep the file encrypted follow and will result in slowing the save process.
Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base: 322756 (https://support.microsoft.com/kb/322756/ ) How to back up and restore the registry in Windows
Option 1. Remove the encryption from the Temporary Internet Files/Content.MSO, Content.Word subfolders.
Option 2. Disable EFS encryption support on the server
VALUE: 0 = encryption is ENABLED, 1 = encryption is DISABLED
Option 3. Enable the server for Trusted Delegation. This will allow the server to impersonate the client and create a profile with certificate for encryption on the server.
Enabling Delegated Authentication https://technet.microsoft.com/en-us/library/cc780217(v=ws.10).aspx
You can save the file locally, then drag and drop the file to the desired network location.
By default, the subfolders used by Excel, Word and Powerpoint are: Content.MSO and Content.Word
The subfolders are very hidden, system protected subfolders of the Temporary Internet Files folder
Example: C:\User\<user name>\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.MSO
On Windows 8 and Windows 10, the Temporary Internet Folder is now "INetCache"
Example: C:\Users\<user name>\AppData\Local\Microsoft\Windows\INetCache\Content.MSO