UPDATE: some people notified me about this not working for SharePoint. Too bad, I didn't test and read it well. Sorry for that!
Something which is hard to explain to customers is why they can edit a document in SharePoint only via the document context menu 'Edit in Word' and not directly via the link to the document. Especially when a link is provided in an email message, it is annoying to see that you can only open a document in read only mode.
Today I got the question if it was possible to create a list of links directly to documents to edit, without opening them in read-only mode. Good question, good reason to find a solution!
The behavior is managed client sided. SharePoint uses javascript to open a document in edit mode. It looks something like this:
javascript:editDocumentWithProgID2(/'path/document.doc','Word.Document','SharePoint.OpenDocuments');
The problem with this is that regular SharePoint users cannot link to the document directly and it is not really user friendly.
During my search I ran into a MS KB article that explained that you can change the behavior of opening document while browsing in the registry. The steps to take:
1. Quit all Office 2003 and 2007 Office programs that are running.
2. Click Start, click Run, type regedit in the Open box, and then click OK.
3. Locate and then right-click the following registry subkey: HKEY_CURRENT_USER\Software\Microsoft\Office\<version_number>\Common\Internet
4. Point to New, and then click DWORD Value.
5. Type OpenDocumentsReadWriteWhileBrowsing, and then press ENTER.
6. Right-click OpenDocumentsReadWriteWhileBrowsing, and then click Modify.
7. In the Value data box, type 1, and then click OK.
8. In the File menu, click Exit to quit Registry Editor.
For more information about this check out the KB article.