i used boot camp assistant to partition my macbook HD. everything was going well, and then it told me to restart my computer by holding down the power button. i pressed it until the screen went black and then took my finger off. i then pressed the power button again and my computer started up as normal. a guide i was following told me a white screen should appear with the apple logo and a progress bar. this didnt appear, but i noticed the amount of GB available on my HD icon on the desktop had gone down by the amount i set the partition to. i checked disk utility to see if the partition had been made but there was no partition. now when i try to create a partition using boot camp assistant again it tells me im not allowed. has anyone experienced this before or could anyone give me any help?