To identify if a disk is external and manage its display in the "Safe Removal" list:

Registry Check: Review registry settings related to USB and IDE devices to identify removable drives.

Device Properties: Use system tools to query the properties of the disk, which can confirm whether it is external or removable.

Context Menu Behavior: Modifying certain registry settings may influence the appearance of the "Eject" option, but it doesn't directly control context menu visibility.

Device Notifications: Set up notifications for when a disk is connected to determine if it's an external device.

Be careful as improper modifications can affect stability and performance.