Try the following:
1) Turn off the controller and unplug it from the USB port.
2) Close Spark (kill it if it's freezed too)
3) Connect the controller again to the computer's USB port and turn it on. If it doesn't come back on, try every other USB port or try using a powered USB hub or use a power supply so it receives power.
Sometimes, windows 7 USB power management goes beseark and doesn't supply enough power, even it usually does on that port.
Rebooting the computer can also solve this issue of correct USB powering output.
4) After getting the controller powered (even if unresponsive, don't worry) start Spark (software) and wait for it to detect the controller, complain about it not being updated and accept the update option.
If I remember correctly (when this happened to me) I had to try some of these steps 2 or 3 times, before if worked.
I'm obviously writing this by heart, so I may be forgetting something, so if it doesn't work like I described, I can try and check what I forgot about this