The ClearCustomProperties method deletes all custom properties
HRESULT ClearCustomProperties();Return values:
S_OK on success or COM error codeNV_NOT_INITIALIZED - Initialize was not calledNV_UNKNOWN_PROFILE - no profile loaded
HRESULT ClearCustomProperties();S_OK on success or COM error codeNV_NOT_INITIALIZED - Initialize was not calledNV_UNKNOWN_PROFILE - no profile loaded