By Catherine / Last Updated February 26, 2020

Someone install Windows 7 and get the error message as the following:

"Setup was unable to create a new system partition or locate an existing partition."

The reason maybe that you want to install Windows 7 as a dual boot on a different partition, but the hard drive already have more than one partition. Or the drive was partitioned before installing Windows 7. What you want to do, to have Windows 7 install the 100MB (common sense) Microsoft hidden system reserved partition before the system partition, is to start over as a clean installation. Choose Custom (Advanced), then when you come to the "where do you want to install Windows"? Delete all the partitions on the 250GB(suppose) drive.

Also not have any other hard disk connected, and if possibly make the USB drive(if you install Windows 7 from USB flash drive) folder Read Only, so the system reserved partition won’t get placed on it.

Give that a try, and if all goes well, in Windows built-in Disk Management, you will see the “hidden” Microsoft reserved 100MB system partition, followed by your Windows7 system partition, boot, crash dump, page file partition.

You can complete delete your other bigger (mentioned 250GB) partition. The premise is you want to try Multi-System, you already have Windows XP on your computer. At first, delete the larger partition that you plan to install Windows 7 on it. If you can‘t, you can also split it.

Above solutions require manipulations with your disk (eg. formating, changing partition structure, etc.), following are tricky methods.

Method 1

  • When you see the error information - remove the flash drive from the computer first.

  • Press exit (red cross in the top right corner).

  • Start installation from the beginning (without reboot).

  • After selecting Windows 7 edition you will get new error. Neglect it.

  • Press OK in error window, you will be redirected to installation main menu.

  • Insert your USB flash drive into the computer.

  • Install Windows.

  • Finished.

Method 2

Above solve "setup was unable to create a new system partition" method works well on Windows 7. However, when you install Windows 8, Windows 8.1 or Windows 2008. Above method may not help, don’t worry, following is another tricky method will be appropriate for any Windows versions.

Primarily you just need to copy all installation files from USB flash drive to your HDD (or SDD) drive and make bootable cd, then continue installation from HDD to HDD.


  • Boot Windows installation from USB flash drive.

  • Press Shift+F10.

  • In console type diskpart.exe and press enter. In this program execute following:

  • select disk=0. Disk 0 is your destination drive, so be careful, all information on this drive will be removed.

  • create partition primary size=xxx, where xxx – is the size of new partition.

  • select partition=1.

  • active.

  • format fs=ntfs quick.

  • assign.

  • exit, now you have bootable drive C.

  • Navigate to USB flash drive, in my case: cd d:.

  • Copy all files from USB drive to C: drive: xcopy d: c: /e /h /k.

  • Go to boot folder: cd boot.

  • Make you C: drive bootable with following command: bootsect /nt60 c:.

  • Put off USB flash drive from computer and restart them.

  • Install Windows.

  • Remove unnecessary menu item from bootscreen.

  • Run cmd.exe as Administrator

  • See boot menu list bcdedit

  • Find Windows Setup and copy identifier

  • Run bcdedit /delete {identifier}

  • Enjoy!

This article is mainly about "setup was unable to create a new system partition", but mentioned tools as Disk Management, diskpart.exe. Operations as creating partition, deleting partition, splitting partition. Many of them are related to partition.

In fact, optimizing disk partition and partition operations are important and often come when using computer. Windows disk manager and diskpart are able to do some partition operations, but still have many limitations. So, own a great partition software is necessary.

AOMEI Partition Assistant is a partition software can completely replace Windows disk management and diskpart. Not only because its functions are more than the two former utility tools, but also it’s easier to use than them on Windows.

Create Partition with AOMEI Partition Assistant

Features of AOMEI Partition Assistant please refer to here.

Some of the highlights:

AOMEI Partition Assistant supports wildly Windows OS: Windows 8.1, Windows 8, Windows 7, XP, Vista, and 2000 (both 32 and 64bit). Windows Server 2003/2008/2011/2012/2000.

For PC user, the most common editions are AOMEI Partition Assistant Standard Edition, AOMEI Partition Assistant Professional Edition. There are many advanced features in the pro edition and you can upgrade to the paid edition. For Windows Server users, common editions are AOMEI Partition Assistant Lite Edition and AOMEI Partition Assistant Server Edition. More information please click here.