My laptop is running Win 8.1 with all the Sony software and partitions installed on it. In fact, there are 7 partitions as follows: 1. SONSYS 260/235 MB OEM (Reserved) 2. Windows RE Tools 1.4GB/535 MB Recovery 3. (no name) 260/208 MB System 4. (no name) 128/128 MB MSR (Reserved) 5. Drive C 218.3/127.7 GB Primary 6. Drive D 215.2/79.7 GB Primary 7. Recovery 30.3/5.0 GB Recovery After changing 'UEFI' to 'Legacy' in the BIOS settings and attempting to clean install Win 10, the system gives me the following error messages for both Drive C and D: "Windows cannot be installed on this disk. The selected disk is of the GPT partition style." My question is: If I delete each partition (i.e. all 7 partitions) during Win 10 setup and then reformat using the format tool that comes with the installer, will it be the correct MBR partition style, thus enabling me to clean install Win 10? There is no information on either drive partition that needs to be saved - it has already been backed up to another external drive.