Here’s how to stop the low disk space warning on Windows XP with one simple command! Open Command Prompt (Run > cmd) as an admin and type:
REG ADD "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer" /v NoLowDiskSpaceChecks /t REG_DWORD /d 1 /f
Restart your PC, and the warnings will be gone!