Sd4hide.exe -

sd4hide.exe is a legacy utility tool, most active in the early-to-mid 2000s. Its primary purpose was to bypass the SafeDisc 4.x copy protection scheme used on many PC game CDs/DVDs. By hiding the presence of virtual CD/DVD drives (like Daemon Tools or Alcohol 120%), it tricked the game into thinking the original physical disc was in the drive.