One thing you could try is to use Sleep instead of shutdown.
If all works well your PC should wake up exactly as it was when it went to sleep.
I don't use WMC but I think that might work better with sleep than what i mostly use (Arcsoft TME).
You may have to play with it a bit to see what "state" you should have WMC in before going to sleep.
If you do get it working, wake up is much faster than a boot up.
My primary PC is a HTPC/General Purpose, and i don't re-boot often, min 1 per month for patch Tuesday.
All my normal programs are open when the PC wakes up...
hope this helps,