Why Backup C Drive in Windows 10?
Sometimes you have to backup C drive in Windows 10, 8, 7 to external hard drive to avoid the following situations:
Virus attacks.
Improper operation cause system crash.
Blue screen Of Death (BOSD)or black screen of death.
Physical disasters, flood, earthquake, storm, etc.
Disk bad sector problem occur, etc.
Once you backed up C drive, you could restore system files if the system boot failure to avoid the system reinstallation. How to backup C drive Windows 10? Before that, you have to figure out the difference between boot partition and system partition.
Boot Partition vs System Partition
The system partition is an active primary partition that contains the boot loader to boot the operating system and store the boot sector. The boot partition is the disk partition that contains the Windows operating system and related system files.
The system partition and boot partition is the same before Windows 7, signed for C drive letter. And you could input the %systemroot% in Windows File Explorer to locate the Windows system folder C:\Windows. Since Windows 7, system partition (hidden, no drive letter) and boot partition (C:\) is separated created by Windows Setup. Hence, there may be some other hidden system partitions like EFI system partition, Recovery partition, System Reserved partition, etc.
Therefore, please open disk management to check if there other hidden system partitions on your Windows 10 computer. If there only one C partition (C:\), back it up now; or you have to backup all the hidden system partitions and C drive to protect your Windows 10.
3 Ways to Backup C Drive for Windows 10
To backup C drive in Windows 10, you can’t directly copying all files and applications in C drive to another destination, because this way cannot ensure system will be bootable and may cause data loss.
As a matter of fact, there are three ways to create a system backup in Windows 10:
Backup C Drive with Backup and Restore (Windows 7)
Fortunately, Windows 10 built-in a backup software named Backup and Restore (Windows 7). you could perform Windows 10 backup C drive. Here is the step-to-step guide to backup Windows 10 OS to external hard drive:
1. Connect the external hard drive to your Windows 10 computer and please go to the path:
Start -> Settings -> Update & Security -> Backup -> Go to Backup and Restore (Windows 7) -> Create a system image.
2. Select the external hard drive as the destination to backup Windows 10 to external hard drive.
3. The C drive, EFI system partition, Recovery partition will be choose by default, click Next button.
Tip: At this moment, you could choose other partitions to backup.
4. Confirm the settings and Press Start Backup to create system image Windows 10 C drive.
Sometimes, you may get the drive is not a valid backup location error while backing up Windows 10 to USB flash drive, even the USB flash drive is formatted as NTFS, create a system image still not working for USB drive. It’s probably because the USB drive storage space is not enough. Please try a larger enough USB flash drive, 128GB, 256GB, or 1 TB. Or backup Windows 10 to OneDrive, Dropbox, Google Drive, etc.
Note: You could not restore files from the image file created by Windows backup and restore.
Wbadmin Backup C Drive in Windows 10
If there only C partition, no other hidden system partitions in your Windows 10, you could try Wbadmin to backup C drive with the following steps:
1. Input CMD into the Windows Search box, and run Command Prompt as administrator.
2. Type the below command to backup C drive to D partition:
Wbadmin start backup -backuptarget:D: -include:C:
That’s it.
Backup C Drive with free Windows 10 backup software
Another option is trying the professional yet free Windows 10 backup software - AOMEI Backupper Standard. This freeware not only backup Windows 10 OS (C drive and other hidden system partitions) but also enables you to backup entire Windows 10 computer, and you could backup individual partition for Windows PCs, like Windows XP, Vista, 7, 8, 8.1 and 10(32-bit and 64-bit).
Now, you could download AOMEI Backupper Standard to have a try, and follow the system backup guide to backup C drive in Windows 10 automatically:

Download Freeware
Win 10/8.1/8/7/XP
Secure Download
1. Choose Backup tab and then select System Backup on the main console of AOMEI Backupper.
2. All the system partitions (including C drive) will be selected to backup.
3. Choose a destination location to save Windows 10 image backup file.
4. Tick the Schedule option to automatically backup Windows 10 OS to external hard drive or other locations as you wish.
5. Press Start Backup to backup C drive and other system partitions easily and safely.
Please click Finish to complete the process for system backup Windows 10. Then you will get an Windows 10 image backup file on the destination.
You could perform selective file restore with the Windows 10 image backup file created by AOMEI Backupper. Now please create a WinPE bootable media if the Windows 10 computer refuse to boot, you could use the bootable media to boot up the Windows 10 computer, then restore Windows 10 system files with the system image file created before, and there is no need to reinstalling Windows operating system, then everything will be fixed.
Besides, you could use AOMEI Backupper to backup entire Windows 10 PC to another location, automatically backup files to an external hard drive in Windows 10, etc.
Brief Summary
It’s easy to backup C drive in Windows 10 to protect your operating system in case of system failure. Find the suitable way to create system backup in Windows 7, 8, 10.
As for Server users, please try AOMEI Backupper Server to enjoy more advanced features, like restore to dissimilar hardware computer, Command line utility, sync files as soon as possible with Real time file sync feature, migrate Windows 10 to SSD without losing data, create Windows 10 incremental or differential backup, etc.