How do I stop a windows 7 software raid

I have a windows 7 software raid running and it is working great. I want to add a new disk to the raid but I can not seem to delete or format the raid at all.

I booted into safemode and when I tried to format the drive I got the message,
"drive is in use . another program or process is using the drive, do you want to format anyway?"
when i click ok it tells me to quit disk utility or any process that is showing the drive contents.

I am a bit stuck. Even in the disk management system tool i can not touch the partitions that the disk is using.

I am tempted to just pull one of the raid drives and wipe the whole thing that way, but I want to know the proper way to stop a software raid.

Any direction would be appreciated, For now I will keep digging in the windows7 resource kit

J_NB