oh good grief!
Unless i'm missing the point completely, you've not partitioned your drive at all. Simply havign free space under windoze is totally different. you need to split you 100% partition into two (at least) parts. I personally used Mandrake 7.2 to partition my drive properly, and then rebooted and installed rh71, which is very dumb.. but it works cool. Alternatively, (download and )use fips, under windoze. I also had some success using a program cleverly called 'Partition Resizer'. rh71 will create its own partitions within the free space, so all you should need to do is to reduce the windows partition.
Remember that with large drives you may have problems with the first partition being too large, making the second (i.e. linux) unreachable. Only a problem with older bioses. (i think)