Windows 7 has a disc partitioner built in. You should defrag and backup before attempting this, for safety. Suppose you have a 320GB drive, as I do. I "shrank" my Windows partition to 212GB, which freed up roughly 80GB for my Linux install. There is also a 12GB recovery partition, but I don't touch that. I can restore my desktop to "like new" by booting into that and following the prompts. Like I said, you can create partitions by clicking onto one and "shrinking" it. But as far as the format goes, you can't format to ext2, ext3, and so on. You need a tool like GParted (or a similar tool) to do this with. You can do a lot with GParted, shrink and grow partitions, delete them, make new ones, a lot of possibilites.