Because those players don't need registrations (e.g. BSplayer Pro) and to save settings in installation dir.
Have you tried to install by saying "Save settings in user home folder"?
Plus it's not enough to login with administrator rights, you also need to start the application with admin privileges (right click on the app and click on "Run as administrator")
As an alternative you can try to login with the HIDDEN administrator account (search the internet on how to make it available on log on screen)
@SergioPlayboy in reference to your other post:
If it still says you have not a registered copy also after you register it probably you are using a keygen to create a valid serial... otherwise write to BSplayer team by using the proper
form for support available to legitimate customers