How do I change the active partion in Vista?

Right click computer > manage > disk management > right click partition of choice > set active.

Are you trying to set up BitLocker? If you check MSUpdate there is a BitLocker Drive Preparation Tool that will do everything you need automatically.

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.