I have iMac running Snow Leopard 10.6.1. Upgraded to Parallels 5 w/o incident w/ Windows Vista installed. I now want to install Windows 7. When I start the install process I get message that: "not enough free space on partition C total of 12689 mb of free disk space required". Is there a step by step guide available on how I can increase the available free space on "partiton C " so I can upgrade my Vista to Windows 7 ? Thanks for any help.