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Chiglobal  This worked for me try it let me know.

Followed these steps and it installed again:

1. On the domain controller where the ATP Sensor had failed, I searched the registry for "Azure Advanced" (without the quotes), and deleted all keys and subkeys where this was found.   I just made sure it was referencing the sensor.  There were several keys that needed to be deleted from HKCR and HKLM.   Just to be sure to be sure....make a backup of the registry before you delete the keys.

1. I deleted the folder C:\Program Files\Azure Or Windows Defender Advanced Threat Protection Sensor

1. Manually re-installing the sensor worked and it is reporting as expected in the portal.   

https://techcommunity.microsoft.com/t5/microsoft-defender-for-identity/manually-uninstall-the-azure-atp-sensor/m-p/238344