Registry.CurrentUser.DeleteSubkey issues VS2026 VB10

Given the following:

Code:

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My.Computer.Registry.SetValue("HKEY_CURRENT_USER\MyTestKey", "MyTestKeyValue", "This is a test value.")

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I wish to do one of the following:
a. Delete "MyTestKeyValue" or
b. Set "This is a test value" to Nothing.

This is in part to reset settings such as Background Color, Width, Height, Position-x, Position-y (all are REG_DWORD).
DeleteSubKey is not working. Error says key does not exist.
SetValue to Nothing also throws errors.

Thanks in advance.