There is a problem with a Windows patch (MS06-015) which among the symptoms are Office programs (Excel, Word, Etc) hang when opening files from the network. This is actually caused by the update conflicting with installed HP software. The problem is with the file Verclsid.exe. Renaming the ”c:\winnt\system32\verclsid.exe” fixes the issue. Microsoft also has published an article with the official Microsoft fix. 

Microsoft KB 918165 - Problems in Windows Explorer or the Windows shell after you install security update MS06-015

 

 It behaves just like the old Word macro virus where you could not perform a “Save As” and Excel and Word would hang when opening/saving a file using a network share.