How do I mirror my hard drive onto a larger hard disk?

Windows, OS X, or Linux?

Many times the new hard drive will have a utility on the disc it came with to copy a mirror of your old hard drive onto it. If not there is a slew of after market products that you can use to mirror copy a hard drive, like HDC Clone, Acronis True Image Home, Spotmau PowerSuite 2012, etc. You can clone the whole drive or just a partition or two. You have more options than I would have space to really tell you.