If you encounter this error message this is most probably due to the fact that you are not logged in as an administrator. When updating DataLab needs to have write access rights in certain directories which are denied by Windows if you are logged in as normal user.
Solution: Either (1) login as administrator and perform the update, or (2) close DataLab and restart it by right-clicking the DataLab icon on the Windows start menu and selecting "run as administrator". Thereafter you can perform the update. When the update is finished you can work again under normal user rights.