I had the same problem on my Toshiba Z30t running Windows 8.1 64-bit Pro. Soon after unboxing it, I ran Windows Update, and after 30 or so updates were downloaded and installed, TiWorker.exe reared its head and pretty much took over my laptop.
After a bunch of googling over the past couple days, I ended up following the advice from this bit-tech column about Microsoft's botched update of the servicing stack.
Opening command line in Administrator mode, I executed the Deployment Image Servicing and Management (DISM) command with the following switches:
DISM /online /cleanup-image /restorehealth
And after a reboot, no more TiWorker.exe hogging my Z30t, even when I've left it idle.