How to Fix the Setup was Unable to Use the Existing Partition Error in Windows
There are all kinds of installation problem that could pop up while attempting upgrading or install another Windows operating system. Setup was unable to use the existing partition because system volume does not have required free space is one of the common error, which usually appears in installing a second Windows system on the same hard drive or more than one hard drivers have been connected to your computer. Just like the following thread on the Microsoft forum:
I want to install windows 10 alongside windows 8.1 pro and I have created a new partition installing windows operating systematization (60GB) to install windows 10 on. While choosing The considered partition windows displays error: “setup was unable to use the existing partition because the system volume does not contain the required free space.” When selecting other partitions, again windows gives that error. How to fix the error?
If you are trying to install the dual system on your hard drive, that means the hard drive is not totally blank. Since you have installed a system before, Windows system would create a system reserved partition on your hard drive automatically, which contains boot manager and boot configuration data. The data of the first system has been saved on the system reserved partition, so just create a new partition to Setup was Unable to Use the Existing Partition is not enough, you have to format the system reserved partition. Then you can install the second system successfully.
Solution 1. Format System Reserved Partition to Fix Unable to Use the Existing Partition Error
If you do want to install the second system on your hard drive or upgrade to new Windows without caring the first system, to delete and format the system reserved partition and other boot partition is the best choice. Let’s see how it works.
Step1 to fix Setup was Unable to Use the Existing Partition: Since installing the new system on the partition you have created, when you choose the partition and click Next button, the error setup was unable to use the existing system partition because it does not contain Setup was Unable to Use the Existing Partition the required free space shows; just like the following image.
Step2: Then you can choose the system reserved partition and click format button. If you format this partition, any data stored on it will be lost showing, and then click OK to continue the following step;
Step3 for Setup was Unable to Use the Existing Partition: After finishing format system reserved partition, just click the partition you want to install Windows and click Next. Then the Windows will install automatically. (Setup was Unable to Use the Existing Partition)
Solution 2. Extend System Reserved Partition to Install Dual Systems With AOMEI Partition Assistant (Setup was Unable to Use the Existing Partition)
If you would like to keep the current Windows system and install another system on the same computer, to format the system reserved partition is not recommended. The best solution is to extend the system reserved partition to expand the free space. Disk management utility built in Windows doesn’t allow to extend system reserved partition. Here you can give a try with free partition software AOMEI Partition Assistant.
AOMEI Partition Assistant is a powerful software to manage your hard drive and partition. It will also work with ease, even you are a novice, you could handle it. The advanced utilities equipped in it provide more comprehensive protection and smarter partition operations. The Here we will introduce how to extend system reserved partition with it.
Suggested: Enter Windows 10 Safe Mode
Step1: Download the freeware, install and open it.
Step2. Right-click the C drive, and select “Resize Partition” feature. Then create about 500 MB of unallocated space. Usually, the system reserved partition for Windows 10 is about 500 MB, for Windows 8 is about 200 MB and Windows 7 is 100 MB. So 500 MB is enough.
Step3. Please tick “I need to move the partition” button and drag the bar from left to right. Then, the unallocated space will be next to the system reserved partition. Click OK.
Step4. right click the system reserved partition and choose “Resize Partition”, drag the bar to extend partition with the unallocated space.
Step5. Check all the pending operations, make sure there is no problem and click Apply to execute all the process.
Conclusion about Setup was Unable to Use the Existing Partition:
After finishing to extend SRP, insert your Windows installation DVD or USB bootable disk into your computer. Then choose the language and keyboard layout to install the new Windows system successfully. After finishing installation and boot your computer for the first time. Furthermore, you need to choose an operating system as default boot system. Choose the one you prefer to. You can still use it to convert mbr to gpt.