After a reinstall of windows home premium7(GA-P55A-UD4P MB, Seagate Barracuda 7200.12 HD,Bios setup for AHCI,(( regedit for AHCI done))windows didnot allow me to format the system partition(first time Ive experinced that). Everything seems to run great, so I dont know if "101MB Unallocated" also...