Windows 7 - Shell context menu option does not work when many items are selected

 What

After selecting 17 items my client couldn't print anymore these documents (right click) in Windows Explorer.

 Problem

Shell context menu option does not work when many items are selected.

 Solution

Microsoft implemented an security setting for not selecting anymore documents then 16. to select more documents we need to add the following registry key:

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer]
"MultipleInvokePromptMinimum"=dword:00000010

Which disables the safety feature to remove options when a lot of items are selected, the documentation on microsoft's web site http://support.microsoft.com/kb/2022295 says that setting it to 16 (as above) should let it treat as unlimited, but in my experience this did not work. Setting it to 16 allowed me to register up to 16 items at once. As soon as I selected more than 16 items it only registered the 1 item I right-clicked on. I found that by setting the registry to higher values I was able to run it on that many multiple items, so setting it to:

"MultipleInvokePromptMinimum"=dword:00000011

allowed my to register up to 17 items at once and setting it to

"MultipleInvokePromptMinimum"=dword:000001f4

allowed me to register up to 500 items at once.