Use Windows Task Scheduler for mounting and formatting a disk on startup. Configure a task to run the imdisk command on startup. Set the user to 'system' and configure for 'Windows 7, WIndows Server 2008 R2'.

Example command line:

imdisk -a -t vm -m R: -s 1GB -p "/fs:ntfs /q /y"

Thank you Olof Lagerkvist! You rock!