Ugghhh... I have a headache. I am trying a clean install of Windows 7, having upgraded to Windows 10, but experience some annoying bugs. Anyway, I bought a new PC without an operating system, then an OEM copy of Windows 7 :-/ So, after attempting this clean install, I got to the stage after choosing 'custom install', and where it asks where I want to install Windows. However... there are 3 different partitions, and it say 'Windows cannot be installed' to any of them for various reasons; Disk 0 Partition 1: System Reserved= (Windows cannot be installed to this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only be installed to GPT disks. Disk 0 Partition 2 = Same as above ^^^ Disk 0 Partition 3 = Same as the first, but with the addition of 'Windows cannot be installed to this hard disk space. The partition was reserved by the computers Original Equipment Manufacturer (OEM).' So... what on Earth can I do? Format one or all of them? If so, which one/ ones? I really have no idea and would greatly appreciate some help. Many thanks.