If you are using the Toshiba Power Saver (or any other software) and you suffer from broken power scheme running Windows you may try this. Open the registry editor and locate the path:
You should find a list of (per default) six additional subkeys numbered 0..5. Those contain the description for the Windows default power schemes Desktop, Laptop, Presentation, Max. Power, Min. Power, Max. Battery. If you find additional subkeys, those were created by any additional power manager and you should be able to remove them w/o any
problems. Afterwards your default Windows settings should be restored and you may be able to install your 3rd party power again — give it a try!