Extend os partition

Guide to extend OS partition drive on Windows 10

As we know, many types of files are writing into the OS partition continuously, so it is very likely Platzmangel after a period of time. Many people ask if it is possible to extend the OS partition without reinstalling or restoring from backup. To extend OS drive on Windows 10, there are 2 options by native Disk Management or third party Festplattenpartitionierungssoftware.

Disk Management only works with specific partition configuration. Professional partitioning software is much more powerful, however, you should take care of your data, otherwise, there is potential data loss risk with unreliable software. In this article, I’ll show you how to extend OS partition in Windows 10 with both Disk Management and safe partition software.

Extend os partition

Extend OS partition with Windows 10 DM

Some people like to use Windows built-in utilities, to extend disk partition, Windows 10 indeed has Disk Management snap-in. However, it is not the best tool, because it has many restrictions.

Together with Extend Volume functionality, there is Shrink Volume that is able to decrease size of allocated partitions. Some people try to shrink D and then extend the OS drive, actually, it is impossible. Windows Disk Management can only shrink drive D to the left and produce Unallocated space on the right side, but to extend C drive with Extend Volume, Unallocated space must be on the left side of drive D. This is the reason why many people feedback that Extend Volume ist für Laufwerk C deaktiviert..

As you see, I can’t extend system partition after shrinking drive D:

Die Lautstärke kann nicht erweitert werden.

The only option to extend OS C drive in Windows 10 Disk Management is by deleting the adjacent drive (D:).

  1. Rechtsklick Fenster on bottom left of the screen and select Disk Management.
  2. Klicken Sie mit der rechten Maustaste auf Laufwerk D und wählen Sie Datenträger löschen.
  3. Klicken Sie mit der rechten Maustaste auf das Laufwerk C und wählen Sie Volumen erweitern.
  4. Klicken Sie einfach auf Weiter bis Ende im Fenster des Assistenten für die Erweiterung von Volumes.

Vorsicht Do NOT do this if you installed programs to drive D. Remember to back up or transfer files before deleting.

Extend OS drive with partition software

Mit Partitionssoftware wieNIUBI Partition Editor, können Sie extend the system partition C without deleting other drive.

It is able to shrink drive D to the right side and produce Unallocated next to C drive, then you can easily extend the OS partition in Disk Management or with NIUBI.

Steps to extend OS partition C on Windows 10:

Schritt 1: Herunterladen NIUBI Partition EditorKlicken Sie mit der rechten Maustaste auf Laufwerk D und wählen Sie "....".Resize/Move Volume“.

Größe des Volumens ändern

Drag the left border rightwards to shrink it, you may also enter an amount in the box behind Nicht zugeordneter Speicherplatz vorher. (1024MB=1GB)

Schrumpfen D

Unallocated space is produced on the left side of D.

Antrieb D geschrumpft

Schritt 2 Rechtsklick C drive and select “Resize/Move Volume” again, drag the rechter Rand rightwards to combine the Unallocated space in the pop-up window.

C erweitern

Click OK, system partition C is extended to 50GB, click Apply on top left to execute.

OS-Partition erweitert

Tipp NIUBI Partition Editor is designed to work in its own virtual mode, the 2 operations are listed as pending on bottom left. If you want to cancel these operations, click Undo. To modify real disk partition, click Apply to take effect

Die ausstehenden Vorgänge sind als Prüfen kann unter Windows ohne Neustart durchgeführt werden.

Watch the video how to extend OS partition in Windows 10:


Windows 10 native Disk Management can only help you extend the system partition by deleting the adjacent partition. The destructive way is not suggested. The best way is running safe partition software to shrink other partitions. Better than other tools, NIUBI Partition Editor00 has Virtueller Modus, 1 Sekunde Rollback, Hot-Resize, Stornieren-nach-Wille technologies and advanced file-moving algorithm to help resize and extend disk partition fast and safely.