At work we suddenly started to get complaints of slow network access to files on our windows.
The symptoms were documents taking about 1 minute to open when double clicked and slow displaying of properties when right clicking and chosing properties.
One strange thing was that if you opened the same documents from inside the application itself then the documents opened as quickly as normal. Also it didn't matter whether the network location was a mapped drive or if the user browsed to a network location. Both ways were slow.
We finally found the solution when we came across a post here
So on the computer that was having issues we ran
in a command window.
Then we quickly double click a document on a network share that was opening slowly.
We then waited for the command window to finish running the command. Once finished we looked for SYN_SENT at the end of a line.
When we found the entry we looked for the network computer name in the entry. When we pinged the name of the computer we found that it wasn't responding.
Next we looked through the registry for the offending name and found that it was being referred to a few times.
There were multiple references to the computer in the location of an illustrator executable but I'm not sure this is relevent
When the entries were deleted all documents that were double clicked opened up straight away.
Thanks to HowToTroubleshoot