Command Line Character Completion The /f:on command sets the completion character to CTRL+F (0x6) and CTRL+D (0x4). The user specific settings take precedence over the machine settings. The command line switches take precedence over the registry settings. File and Directory name completion is NOT enabled by default (/f:on|off): HKEY_LOCAL_MACHINE\Software\Microsoft\Command Processor\CompletionChar HKEY_LOCAL_MACHINE\Software\Microsoft\Command Processor\PathCompletionChar HKEY_CURRENT_USER\Software\Microsoft\Command Processor\CompletionChar HKEY_CURRENT_USER\Software\Microsoft\Command Processor\PathCompletionChar A tab is a decimal and hex value of 9 / 0x9. The default is 0x40 (64d), completion disabled. If /f:on is not specified on the command line, it will use HKCU or HKLM defined settings. 0x4 represents CTRL+D and 0x6 represents CTRL+F. You can use 0x0, 0xd, or a value greater than or equal to 0x20 to disable character completion. If you use the console Paste function to enter text into a CMD window, you might trigger completion if the characters you paste contain completion characters. 0x20 is space bar (completion disabled). The completion char settings in the registry have a range of: 0x0 | 0x1–0x1F | 0x20 the first and last being off settings. [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Command Processor] "AutoRun"="" "CompletionChar"=dword:00000040 "DefaultColor"=dword:00000000 "EnableExtensions"=dword:00000001 "PathCompletionChar"=dword:00000040 [HKEY_CURRENT_USER\Software\Microsoft\Command Processor] "CompletionChar"=dword:00000009 "DefaultColor"=dword:00000000 "EnableExtensions"=dword:00000001 "PathCompletionChar"=dword:00000009 "AutoRun"=hex(2):63,00,3a,00,5c,00,61,00,62,00,63,00,2e,00,63,00,6d,00,64,00,00,00