The HDD diags are the only thing that will not run on UBCD? Can you browse the hdd of the netbook while booted to UBCD? What sata mode is the harddrive set to in the bios? Could be an issue there...I use ubcd all the time. On certain models, changing the sata operation mode to ahci or whatever solves some funky problems such as bluescreens and lockups, be sure to change it back before booting into windows though...just a thought. Good luck!