If you're looking for a PC version of GarageBand, Mixcraft is about as close as you're going to get.
It enables you to record an unlimited number of audio and MIDI tracks (a cheaper version, Mixcraft 6 Home Studio, is available, but this restricts you to 16) and does so via a friendly and intuitive interface. A decent selection of instruments and effects is provided (you'll get more if you shell out for the top-of-the-range Mixcraft 6 Pro Studio), and you can even use the software to add scores to your videos.
Running to some 6000 loops, Mixcraft's sample library is vast, which is great news if you're looking for an easy way of making tracks quickly. There's support for the ubiquitous VST format, which means you have access to more instrument and effect plugins (both free and chargeable) than you'd ever need.
Although it's often compared to GarageBand, Mixcraft is actually a more capable DAW in certain respects - particularly when it comes to mixing. It might have made its mark as an application for entry-level users, but if you use it to its full potential, it'll be a long time before you outgrow it.
Buy Acoustica Mixcraft 6