Word/Excel Documents Slow To Open
When opening a Word document, Word seems to pause for a long time, before finally opening the document after a few minutes. The Task Manager shows that Word is “Not Responding”, and all the CPU activity is in the System Idle Process.
Outdated Network References
This can occur if the document was created with a template on a network path (such as \\SERVER\Documents) which no longer exists. Word attempts to resolve the server name, and eventually times-out. This problem most often occurs when old servers are taken off the network, or when opening files created on networks other than your own.
One remedy is to open the document and assign a new template. However this is impractical in an environment with many documents. But the problem can be worked around by creating a local CNAME mapping in DNS which causes the old server name (say SERVER) to resolve to the correct server name (say SERVER2.domain.local). Creating a share name on the new server which matches the share name referenced may also be necessary. Thus Word can quickly resolve the name and open the document properly.
If you cannot surmise the old server name, using a Hex viewer to examine the file will reveal the path Word is trying to resolve.
Note that, due to the way workstations cache DNS entries, the new mapping will take a short while to take effect, but it can be forced by running ipconfig /flushdns on each workstation.
Some more technical methods to deal with the issue may be found here.
File Validation Add-In
Another cause of Word and Excel documents opening slowly when opened from a network share is if the Microsoft Office File Validation Add-In is installed. Uninstall it via Control Panel. Or run the following commands from an elevated command prompt:
reg add HKCU\Software\Policies\Microsoft\Office\11.0\Word\Security\FileValidation /f /v EnableOnLoad /t REG_DWORD /d 0