PowerShell Script to Delete a Checkpoint (Snapshot) using Remove-VMSnapshot

To delete a checkpoint in Hyper-V, use the following instructions.
Start PowerShell on the computer where the virtual machine is located.
Type the following command and press Enter to get a list of snapshots
Get-VMSnapshot -VMName TestVM
Take note (copy) the snapshot name you wish to remove
Run the command below to remove the snapshot
Get-VMSnapshot -VMName TestVM -Name “Name Of Snapshot” | Remove-VMSnapshot
You can also run the below to remove all Snapshots
Get-VM TestVM | Remove-VMSnapshot -Name *
To remove any Snapshots older than a given number of days use
Get-VMSnapshot -VMName TestVM | Where-Object {$_.CreationTime -lt (Get-Date).AddDays(-90) } | Remove-VMSnapshot
As soon as the checkpoint is deleted, Hyper-V will start the merge process in the Hyper-V Manager. Depending on the size of the virtual hard disk, the merge process may take some time so be patient.
If you need to export the virtual machine, you will be able to proceed once the merge is complete.