For some reason, the Tab key that auto-completes paths and filenames on the command prompt (cmd), of my Windows XP machine, stopped working.
Pretty strange but anyway, here is how I managed to fix it:
1. Go to Start -> Run, type “regedit”
2. Navigate to HKEY_CURRENT_USER\Software\Microsoft\Command Processor
3. On the right, double-click on the “CompletionChar”, type “9” and press OK.
4. On the right, double-click on the “PathCompletionChar”, type “9” and press OK.
You might need to restart your system after that.