After we began rolling out Windows 7 at the day job, we found our first issue–when people checked out documents from SharePoint 2007, the documents were opened as "Read Only", and the users could not save the edited document back to the portal. The work-around was to save the document locally and re-upload.
After four months of working with Microsoft, we were able to find the solution. The problem was in URLScan, and Windows 7's use of the OPTIONS verb. By default, this verb is blocked. If you look in the URLScan logs (by default, %WINDIR%\system32\inetsrv\urlscan\logs), you'll see an entry like the following (important parts are in bold):
2010-03-19 02:12:15 127.0.0.1 778810668 OPTIONS /<document library path>/ Rejected verb+not+allowed HTTP+method – –
All we need to do to fix this problem is edit urlscan.ini by default, (%WINDIR%\system32\inetsrv\urlscan), find the [AllowVerbs] section and add OPTIONS. Then scroll down a little to the [DenyVerbs] section, and remove OPTIONS from that list. Do an IISRESET and all is well.
For reference, our server platform is Windows Server 2008/IIS 7/SharePoint 2007, and clients are Windows 7 Professional using IE8. This issue does not seem to affect Windows XP users with IE 8.
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