How to detect if device is a Windows365 Cloud PC
It is pretty straightforward to detect if the managed device is a Cloud PC in Intune, setting up dynamic groups to filter policies depending on whether it is a cloud PC: https://learn.microsoft.com/en-us/windows-365/enterprise/create-dynamic-device-group-all-cloudpcs
However, if your security product e.g NAC does not integrate with Intune, then there is a need to fiddle with registry keys.
Below are the registry key and value you can use to filter for cloud PCs
Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SystemInformation
Name: SystemProductName
Data: (it always start with Cloud PC Enterprise followed by the device configuration) e.
Cloud PC Enterprise 2vCPU/8GB/128GB
Cloud PC Enterprise 4vCPU/16GB/128GB
Cloud PC Enterprise 4vCPU/16GB/256GB
Cloud PC Enterprise 8vCPU/32GB/512GB