SearchUnknownExtensions.reg
Code:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ContentIndex]
"FilterFilesWithUnknownExtensions"=dword:1
To Switch off, copy and rename to eg
DoNot_SearchUnknownExtensions.reg
and replace with
"FilterFilesWithUnknownExtensions"=
dword:0