SMP Seesaw is a small, simple application that gives you full control over your dual-core processor Windows system. Select a running process, click the move button, and you can quickly divide your active tasks between your cores any way you see fit. Sure, Windows is supposed to do this manually, but some of us would rather make it happen ourselves, thanks.

A pro version (still free) is available and offers support for up to 32 cores. If you're only running a dual-core, don't bother with it. You can't select multiple tasks and move them all at once as in the basic version. If you do have a plethora of cores, though, get it - you can move a task to a specific core or as many cores as you care to check off.