Had an interesting user problem yesterday/today where a user could no longer use the Actions>Open in Explorer View on a document library.
For information purposes, this was a MOSS2007 environment. The user in question had full permissions to the library. He had previously been using this feature in IE10. He decided to rollback to IE9 due to issues connecting with the the User Profile Service.
We compared his browser settings to another user’s browser settings (with the same permissions). In the original troubleshooting of the problem, we determined that the user had adequate permissions and the following settings were all the same:
SharePoint site was listed as Local Intranet Site
Compatibility view for Local Intranet sites was turned OFF
Pop-up blocker was not preventing the site from opening the Explorer window
Then we began to look at Manage Add-Ons. We noticed that the machine that allowed Open in Explorer View had the SharePoint OpenDocuments Class enabled. The machine that wasn’t allowing it, didn’t show the class at all.
We tried repairing MS Office. We tried running net start webclient. Both to know avail. I kept finding references to Enabling the Add-on… but couldn’t find anything about to add it if it was missing.
What we finally found was that his machine was running the 64-bit version of IE9. When he changed versions from 64-bit to 32-bit IE, Open in Windows Explorer again worked.
I had been stumped before by why some people could use Open in Windows Explorer view and others couldn’t…. now I think I’ve found my answer.
Hope this helps someone else.