Office Authentication Prompt in Vista for Sharepoint Documents

There is an issue in Vista where a user tries to open a document from a document library in Sharepoint and they are prompted by Office to authenticate themselves. This would be acceptable behavior if the user weren’t already authenticated on the MOSS site they were browsing.

For some reason, when XP users try to open the same document from Sharepoint, they DO NOT get prompted for authentication. This is a Vista only issue. I’ve stumbled across many newsgroup posts that claim that this issue has something to do with the “Protected Mode” in IE7. Their recommended solution is to add the Sharepoint site to Trusted Sites in Internet Explorer 7 and to disable “Protected Mode”.

However, even after adding the site to trusted sites in IE and disabling protected mode, the issue still persists. The issue is only replicable after a fresh reboot – once a user authenticates in office, those credentials are cached for future use. Due to this caching in office, many people cannot pinpoint how to replicate this issue.

SOLUTION 1

The First SOLUTION to this issue is to DISABLE the WebClient service in Vista. Here is a quick script that accomplishes this: VistaMossOfficeMossSSOFix.bat Here is the code for those who’d like to incorporate this script into their environment:

net stop "WebClient"
WMIC SERVICE WHERE Caption="WebClient" CALL ChangeStartMode "Disabled"

SOLUTION 2

There is also a second workaround that involves tricking IE to use a fake proxy and to have IE bypass the fake proxy for everything – this workaround is PREFERRED since the first Solutions ends up severing some of the nicer integration features between Office and MOSS (such as the ability to save directly from office on to a sharepoint document library)

In Internet Options, click the “Connections” tab and then click “LAN Settings”:

Click “Advanced” and enter * as an exception to the proxy:

Conclusion

In conclusion, the SECOND SOLUTION seems to be more appropriate as the first one tends to do more harm than good.