created the ubuntu.bin file for dual-booting
Use GRUB for dual booting, not netloader. When you install Ubuntu, opt to install GRUB to the MBR of the drive that holds your C:\ partition.
When you want windows, you can select it from the GRUB menu.
I take it 7.10 worked OK in live mode? It's just that the final release is still some days away. I'd have waited.