And I found another post that says file locking occurs on Win7 also with the Details pane and Popup file tooltips active. (It is in the Microsoft Excel Support Team blog. The item was posted 3 years ago.)
ALL 3 need to be turned OFF:
Apparently as you are double-clicking to open the file, Explorer is trying to read information about the file, to display in the Details, or popup tooltips.
[quote]III. Turn off the Preview Pane, Details Pane and pop ups that show information about file and desktop items
This is a problem that has been reported to affect Windows 7 clients only, not Windows XP. The problem here may have something to do with the Windows Explorer in Windows 7. We are currently investigating this further and will post more information as it is available.
In a Windows Explorer window, do the following:
- Right click on the Start Button.
- Click ‘Open Windows Explorer’.
- At the top left click Organize > Layout
- Uncheck Details Pane and Preview Pane.
- On a Windows menu, click on Tools > Folder Options. In the box that opens up, click on the View tab. Scroll down the list to “Show pop-up description for folder and desktop items” and clear the checkbox and then click OK.