To turn this setting off, editing the key found below and set the value of 'Win95TruncatedExtensions' to '0', to turn the feature back on, set the value back to '1'. 

Key:[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem]
Value Name: Win95TruncatedExtensions
Data Type: REG_DWORD
Data:(0 = disable , 1 = enable)

 

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