How to shrink c drive without losing data on Windows 11?

Dr.Partition is the one of the disk management tools I have used for years.  It is super easy and safe to shrink c drive on Windows 11 or Windows 10.

https://www.techgizz.com/safely-shrink-c-drive-on-windows-pc

You're thinking about shrinking C drive without losing data? Nice move, but yeah. First off, don’t just go straight for the shrink option without checking for errors. Run a quick disk check (chkdsk) first—like, open Command Prompt as admin and type chkdsk /f /r c:. It scans for bad sectors or filesystem issues that could mess things up when you resize.

Next, make sure there's enough free space on C before shrinking. If your drive's pretty full, Windows might not let you shrink it as much as you want, or worse, you might end up with corrupted data. Clear out temp files, uninstall stuff you don’t need, and maybe run Disk Cleanup. Also, defragment your drive—not always necessary with SSDs, but if you’re on an HDD, defragging helps consolidate free space, making the shrink process smoother.

Another thing: To shrink C drive without losing data, avoid shrinking the system or boot partition while Windows is running from it, if possible. Use built-in tools or third-party partition managers that can handle these operations more safely, sometimes from a bootable environment. Lastly, pay attention to the unmovable system files—like page files, hibernation files, or shadow copies—that can block shrinking. You might need to temporarily disable or move these files before shrinking C drive on Windows computer.

Third-party partition management tools are often recommended over Windows' built-in utilities (like DiskPart or Disk Management) for complex partition operations because they handle critical limitations of native tools, especially when data integrity is paramount. Here's why you should a disk partition software in order to shrink c drive without data loss.

Non-Contiguous Partition Handling:

Windows Limitation: DiskPart/Disk Management can only extend a partition if unallocated space is immediately adjacent to it. If another partition (e.g., a recovery partition) sits between C: and D:, extending D: is impossible.

Third-Party Solution: Tools can move/resize partitions to reposition unallocated space next to D:, without data loss.

Dynamic File System Optimization:

Windows Limitation: DiskPart may fail to shrink C: due to:

1. Immovable system files (pagefile, hibernation, system restore points).
2. File system fragmentation (large unmovable files blocking shrinkage).

Third-Party Solution: These tools temporarily disable pagefiles/hibernation, defragment files before shrinking, and bypass system locks.

Visual Operations & Previews:

Tools show a disk map and simulate operations before applying changes, reducing human error.
(Example: Seeing if unallocated space is truly adjacent to D: before committing).

Undo Functionality:

Most tools let you preview and cancel operations before finalizing. DiskPart executes commands immediately (no undo).

I could go with a dedicated disk partition manager when it comes to shrink c drive on Windows 11/10. It is more safe and without losing data!

You can use the diskpart system utility to shrink c drive to d drive without losing data. This is for both Windows 11 and Windows 10.

Important Notes:

Backup First: Always back up critical data before modifying partitions.

Adjacent Space Required: D: must be immediately after C: on the disk layout for this to work. If partitions are not adjacent, you'll need third-party disk partition tools to move partitions.

Unallocated Space: Shrinking C: creates unallocated space after it. To extend D:, this space must be directly before D:.

How to shrink c drive to d drive on Windows 11/10

Press Win + X > Disk Management. Verify that D: is adjacent and to the right of C:.

Press Win + S, type cmd, right-click Command Prompt > Run as administrator.

Run DiskPart:

diskpart
list disk                 > Identify your system disk (e.g., Disk 0)
select disk 0             > Replace "0" with your disk number
list partition            > Note C: and D: partition numbers
select partition 1        > Replace "1" with C:'s partition number
shrink desired=10240      > Shrink by 10GB (replace "10240" with your size in MB)
list partition            > Confirm unallocated space appears after C:
exit

Extend d drive to the new unallocated space:

diskpart
select disk 0
select partition 2       > Replace "2" with D:'s partition number
extend                   > Absorbs the unallocated space
exit

Open Disk Management or run diskmgmt.msc. Confirm D: size increased and C: decreased.

Shrinking C drive on Windows 11 computer can be done safely if proper precautions are taken, Run a disk check (chkdsk) on the C: drive to identify and fix any file system errors before shrinking. But this matter also needs to be done very carefully. Run a disk check (chkdsk) on the C: drive to identify and fix any file system errors before shrinking. Close all programs, especially those that might be using files on the C: drive, to prevent conflicts during the shrinking process.

Although Windows automatically defragments SSDs, defragmenting HDDs can help consolidate free space, making the shrink process more effective. Use the Disk Management tool or third-party partition managers that are reputable. The built-in Windows Disk Management utility is generally safe but may have limitations if there are immovable system files.

Some system files are immovable and can prevent shrinking beyond a certain point. If Windows cannot shrink the partition as desired, you might need to disable certain services or use third-party tools. Do not shut down or restart your computer during the shrinking process. While shrinking C drive without losing data can be safe if done carefully, it always carries some risk of data loss or system issues if something goes wrong. Proper backups and careful preparation are essential.

To shrink C drive without losing data is possible by carefully managing disk space and using built-in Windows tools. Here are some safe and effective steps:

1. Use Disk Cleanup
Press Windows + R, type cleanmgr, and hit Enter.
Select drive C:.
Check the boxes for files you want to delete (e.g., temporary files, system cache).
Click OK, then "Delete Files."

2. Uninstall Unnecessary Programs
Go to Settings > Apps > Installed apps.
Sort by size to identify large programs.
Uninstall programs you no longer need.

3. Manage System Restore and Shadow Copies
Right-click This PC, select Properties.
Click System Protection.
Select C: drive, then click Configure.
Reduce the disk space used for restore points or delete older restore points.

4. Move Files to an External Drive or Another Partition
Transfer large media files, documents, or downloads to an external drive or different partition.

5. Use Storage Sense

Go to Settings > System > Storage.
Turn on Storage Sense to automatically free up space by deleting temporary files.

6. Disable or Reduce System Restore Points (if needed)
Be cautious: this will limit your ability to revert system changes.

7. Resize Partitions (Advanced)
If you have unallocated space or other partitions, you can use Disk Management:
Press Windows + X and select Disk Management.
Right-click on C: and choose Extend Volume if space is available.

Note: Shrink C drive without losing data, or extend requires unallocated space right after C: and careful operation—backup data beforehand.