While trying to do Windows 7 or Windows 8.1 upgrade to Windows 10, users may receive a prompt message that Windows needs more space offering two other options to solve it, one is "Use Disk Cleanup to free up space", the other is "Choose another drive or attach an external hard drive with xx GB available".
What's worse, the upgrading to Windows 10 process fails because not enough disk space with the error code: 0x80070057 or other errors.
Windows 10 needs more space on the system drive to store some necessary files, but your C: drive does not have enough free space, so the error occurs. Usually you need about 8 GB free disk space to upgrade to Windows 10. That some installation packages of Windows 10 may include all the language packs of operating system (OS) may also cause insufficient disk space error, which has been announced as a bug by Microsoft.
There are a few methods to free up disk space and reclaim some extra disk space from C: drive when there is not enough free disk space to install update. You may try one or more of them to resolve this.
Disk Cleanup in Windows 10
Disk Cleanup, a Windows built-in tool, can be used to delete system or non-system files on your hard drives to help you free up more disk space.
1. Right click C:drive in File Explorer, and select Properties. Then you can launch Disk Cleanup there.
2. A few minutes later, Disk Cleanup for (C:) window will pop out. Select types of files that you want to delete, and then click OK to proceed.
3. Now you have deleted unwanted non-system files. Click Clean up system files and select the system files you want to delete as the step above. Under More Operation tab, you also free more disk space by removing programs that you do not use and system restore points.
Not to install latest update
Reduce the needed disk space to install Windows upgrade. When upgrading to Windows 10, don’t let windows install the latest build. If you choose not to install the latest build, it will free up at least 2.5 GB space for windows 10.
Uninstall language packs
Uninstall the language packs that you do not need. To do this, you just run the command: Lpksetup /u in a command prompt and then select the unwanted language packs to uninstall.
Format system drive
Windows 10 upgrade will create a Windows.old folder to save all the data of your previous system. If you have saved a large amount of data on C: drive, then Windows 10 upgrade will need relatively more space to complete the upgrade. If the hard drive does not have extra space to add to system partition, then you can create a backup of your system drive and then format C: drive in the Windows 10 upgrade process. After the upgrade, you can selectively restore files to your system drive.
Extend C: drive without data loss
Extend system drive with free partition software, like AOMEI Partition Assistant. AOMEI Partition Assistant can easily resize partitions or merge partitions when suffering from not enough disk space for upgrading to Windows 10 without data loss.
1. Install and open AOMEI Partition Assistant.
2. Click Extend Partition Wizard.
3. Follow the wizard to extend system drive.
Extending partition with AOMEI Partition Assistant is quite easy and does not require reboot. Besides that, it has much more powerful features than Windows Disk Management, such as Disk Copy, Move Partition, Convert to GPT, Migrate OS to SSD, Windows to Go Creator, etc. Besides this free edition, you can also try the AOMEI Partition Assistant Professional edition to experience more advanced features.