3D Spotlight has updated their Windows 2000 Services Tweak guide.

Protected Storage. Provides protected storage for sensitive data, such as private keys, to prevent access by unauthorized services, processes, or users. If your system contains such sensitive data, or programs with multiple Identities then you should set this to Automatic. If when set to Manual you may find this causes problems with certain programs, e.g. Outlook Express, if so then set it back to Automatic.

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