Scenario: You are logged in and can access a WSS 3.0 site. You go to a document library and open a (say) Word document there. You are asked again for loggin information before the document will open.
There are different solutions for this depending on your client environment.
If you are running XPPro and IE6 then you put the WSS 3.0 site in the Trusted Zone in IE6.
If, however, you are running Vista and thus IE7 then you put the WSS 3.0 site in the Intranet Zone (Trusted doesn't work) in IE7.
(It's also possible that disable Protected Mode in the Intranet zone may help with this but this produces a nasty warning every time which will scare users)
If using IE7 under XPPro it seems to be enough to add the WSS 3.0 site to the Intranet Zone.
Thanks to J. Greg Mackinnon for supplying the information about *possibly* disabling Protected Zone and for informing me when it stopped helping (!)
P.S. Note also this KB Article:
A Microsoft managed groups support person added this text for Vista users:
If the web application is not configured to use Basic Authentication and this issue only occurs on Windows Vista machines, it is very likely that
you are facing a known issue in Windows Vista due to the architecture change in WebDAV Redirector of Windows Vista.
There are two workarounds:
Workaround 1: Stop the Webclient service
1. Click Start > Run, input services.msc and press Enter
2. Locate the Webclient service and then stop it.
Workaround 2: Add a fake proxy server and port in Internet Explorer settings
1. Open Internet Explorer > Click Tools > Internet Options
2. On the Connections tab, click LAN settings.
3. Enable "Use a proxy server for your LAN"
4. Input a fake proxy server address and a fake
5. Check "Bypass proxy server for local address"
After that, you can add the Internet websites' URLs to the Local Intranet security zone so that Internet Explorer will bypass the proxy server to
access these websites.
1. In Internet Explorer' Internet Options
2. On the Security tab, click Local Intranet.
3. Click Sites > Click Advanced
4. Input the Internet websites you usually browse to the list.
5. Click OK twice.