Thanks to Alpine Interactive for the great video and article.  (Update 10/20/14) We ran into this issue a lot with companies running Windows 7 & IE 10.  The following knowledge base article has a great hot fix to resolve the issue.  If the hot fix does not work follow the manual update below.

Set up SharePoint clients to resolve SharePoint Online server slowness when opening documents in windows explorer view, using Office 365.

When using SharePoint online via Office 365 you find it’s a truly cloud offering. Your team can share files and work from anywhere. The same is true of SharePoint administration.  Using SharePoint via the Internet Explorer browser is all well and good, but we find that a large proportion of customers want to actually view files in the traditional windows explorer view.

Open with explorer for SharePoint online for Office 365 gives you the familiar looking windows explorer view, that we find most of our customers actually prefer, especially those opening excel files working with Macros.

You can then do all the regular things like, drag and drop files and folders, create new folders, move or copy and paste files and folders, delete multiple files and folders at one time.
You simply click on your library – then open with explorer in the tool bar. Work in the environment but with all documents on the cloud.
To use SharePoint online files in windows explorer view there are some requirements you need to follow for things to work at their peak. I’ve detailed them in this blog post.

1. Trusted sites

  • internet Explorer – tools – options – Security – Trusted Sites – Sites – add the following and press Add after every item:
  • https://*.lync.com
  • https://*.microsoftonline.com
  • https://*.sharepoint.com
  • https://*.outlook.com

then close.
2. Intranet sites

  • Internet Explorer – Tools – Options – Security – Local Intranet – Sites – Advanced – add the following and press Add after every item:
  • *.lync.com
  • *.microsoftonline.com
  • *.outlook.com
  • *.sharepoint.com
  • then close.

3. Uncheck intranet sites from compatibility view.

  • Internet Explorer – tools – compatibility view settings – uncheck “Display intranet sites in Compatibility View”.

4. Web client service – set to auto. Follow the appropriate step for your operating system:

  • For Windows XP, Windows Vista, and Windows 7; click Start, click Run, type services.msc, and then press Enter. (you may need to ‘run as admin’)
  • For Windows 8, click Start, type services.msc, and then press Enter.
  • In the list of services, locate the WebClient service, and then make sure that:
  • startup type is set to Automatic
  • status in the Status column is set to Started.
  • If it isn’t set to automatic and Started, double-click the WebClient service, change the drop down box to automatic and click Start, and then click OK.

5. Uncheck automatically detect settings, this settings alone originally reduced the time to open the majority of files instantly!:

  • Within Internet explorer – show Menu bar
  • Tools – internet options – Connections – LAN settings – uncheck ‘Automatically detect settings’

6. Even after following all the Microsoft recommendations above, one of our customers had the bizarre experience, whereby they would have to click to open a file multiple times and experience time out messages including SharePoint cannot open file in internet explorer, in between.

This was true of different computers on different networks, we ruled out firewall or office specific network issues. After 2 months of pursuing the issue with Microsoft SharePoint support including running network diagnosis software and server connection performance monitoring, this was the solution.
Run command prompt as admin and type these 2 commands:

  • netsh int tcp set heuristics disabled
  • netsh int tcp set global autotuninglevel=disabled

Disabling these two networking values instantly solved our customer’s intermittent Microsoft SharePoint slow issues.

For the record, Microsoft also recommends installing relevant updates as usual:

http://support.microsoft.com/kb/2629108