I cannot complete command or file name in my cmd using TAB key. What have I modified from default settings?

I cannot complete command or file name in my cmd using the TAB key. When I press TAB it actually inserts a TAB space. What have I modified from default settings?

I am using Windows 7.

Solution 1:

The completion character is configured in Registry. Open regedit, navigate to the key HKCU\Software\Microsoft\Command Processor, and make sure the value CompletionChar is set to 9 (0x9). If such a value doesn't exist, add it (right-click - New - DWORD value) and enter 9 as data.

A possible cause for this is that the system-wide settings (HKLM\Software\Microsoft\Command Processor) have the completion character set to 64 (0x40) by default, effectively disabling completion unless per-user settings override it. If you want, you can change the system-wide setting to 9 (0x9) too.