You can't use NTFS for Solaris and you can't name partitions from Windows. If you're not careful, OpenSolaris installer will take the whole disk.
You didn't say what problems you are having so it's hard to help you. Boot a Linux live CD and change the partition type of the partition you want to use for Solaris to b9. Then boot opensolaris and when you see the desktop, double-click the install icon. -- This message posted from opensolaris.org
