Please help! :-(

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.


Windows Forum Admin
Staff member
Premium Supporter
Microsoft Certified Professional
As long as you have no data on your computer, and you have your Windows 7 CD and it's all you want to go back to you can safely delete all of those partitions as long as there is no data on the hard drive you want.
I wouldn't just format one of them, I would literally delete them all and Windows 7 wll recreate the System Reserved partition. (again make sure theres no data on those that you need)

Also if you upgraded from 7 to 10 and had issues, I would suggest giving Windows 10 another try with a CLEAN installation. Use the Microsoft Download tool to create a bootable Windows 10 USB stick, the latest version will accept your Windows 7 key for activation.