The thing to keep in mind when it comes to PC's, and tablets is that without hardware integrated solutions, you're not going to get anywhere.
Someone in my family recently had a laptop stolen from his office, and we had remote management software installed; thing is, the thieves were smart enough to wipe the hard drive before connecting it back to the network.
The only thing I know of right now that works for PC's at a hardware level is LoJack, and that requires a compatible computer.
My advice: the best insurance is insurance. Aside from that, make your hardware disposable; encrypt your hard drives, and keep good, offsite backups.