If you are able to launch XBpartitioner without it giving any warning signs about the LBA options you should be just fine and wont need to update your BIOS. What you need to do is launch XBPartitioner and set up the drive so that there are two main partitions. You cane make it 137GB on F and 300+ on G or just make sure that the big F patition (400+gb's) is formatted with 32k clusters. When you highlight the large partition in XBpartitioner it will tell you at the bottom what it's going to do and how big the cluster size will be. Just select that and let it format the drive. It should'nt take more than 20-30 seconds. After you've done that you can use Slayers or AID to reinstall all of the apps, just make sure AID or slayers does not format the drive again, only let it install the apps to F or however you have it setup. For the modchip, i dont know much about the DUOX3's but at a quick glance the look alot like the DuoX2's, bank switch and all. I bet you've got the options for 2x 512k Bios'. You can use X2_5035 but make sure it's 512k in size since there is also a 1MB size too and that will NOT work. Also you need to figure out what version xbox you have so as there are two different versions of X2_5035 to be used, one is for xbox's that are version 1.0-1.5 and another used only for 1.6 xbox's. Hope this helps Cheers, NExtel