Solved: Selected Volume is a System Boot Disk and Cannot be Extended

Meet the error “The selected volume is a system or boot disk or was created on a basic disk in an earlier version of Windows and cannot be extended”? Here comes the solution.


By Cherry / Updated on May 12, 2023

Share this: instagram reddit


“I have Windows 2003 32 bit Server and low disk space on C drive. Every time when I am trying to extend the C drive I get the error message saying ‘The selected volume is a system or a boot disk or was created on basic disk in an earlier version of Windows and cannot be extended’. Is there any way can solve this problem and extend the C drive successfully?”

Selected Volume Is System Boot Disk

Why the “The selected volume is a system or boot disk” error pops out?

For many Windows 2003 or XP users, it is really a headache problem to extend system volume when C drive is running out of space because there is no extend volume feature in Windows 2003/XP built-in Disk Management tool. Therefore, some users choose to convert basic disk to dynamic because Windows disk management tool can extend simple volumes. But is this really?

After converting to a dynamic disk, you may receive this error message: "The selected volume is a system or boot disk ..." when attempting to extend C drive. Actually, with Windows built-in disk management tool, you cannot extend a system/boot/striped/mirrored/RAID-5 volume, or a volume was created on an earlier version of windows on a dynamic disk. You can only extend simple or spanned volumes that are not system or boot volumes, as long as there is free disk space available.

How to extend dynamic system volume successfully?

Now that you have known the reason for which why the “The selected volume is a system or boot disk or was created on a basic disk in an earlier version of Windows and cannot be extended” appears, it’s time to figure out how to get around of this problem. Here we would like to share you with an effective solution: turn to AOMEI Partition Assistant Server.

This partition management software is compatible with all Windows Server and Windows PC. With it, you can convert a dynamic disk back to basic and then extend system partition. The following is a demonstration of how to do it step by step. For a free trial, you can download the demo version.

Download Free Demo Win 10/8.1/8/7/XP
Secure Download

Step 1. Launch Partition Assistant to get its main interface as below. Right-click the target disk, and choose “Dynamic Disk Manager”. Then right click the dynamic disk and select “Convert to Basic Disk” to convert the dynamic disk to a basic disk.

Dynamic Disk

Convert Dynamic To Basic

PS.: this conversion won’t delete existing partitions and data on the dynamic disk.

Step 2. Back to the AOMEI Partition Assistant Server. Right-click a partition that has free space for extending system drive, like D drive and select “Resize Partition”.

Note: If the drive has enabled Bitlocker encryption, the "Resize Partition" still works.

Shrink Partition

Step 3. Then drag the slider to the left side to shrink this D partition.

Size Position

Step 4. Then there will be unallocated space after D drive. Now, right click the D partition and select “Move Partition”. In the next window, drag the partition to the left to make unallocated space adjacent to system C drive.

Move Partition

Step 5. Then right click the boot volume and select “Resize Partition”. Then drag the slider to the right side to add into the unallocated space.


Step 6. You can see C drive has been extended. Click "Apply" on the tool bat to submit the operations.



So, under the help of AOMEI Partition Assistant Server, you can effortlessly solve “The selected volume is system boot disk” . In addition, it has many other amazing functions to help you manage disk partitions. For example, it can clone hard disk, move Windows Server to new hard drive, extend system drive without reboot, convert MBR and GPT without deleting partitions, convert primary drive to logical drive without data loss and more. To install this kind of powerful partition manager on unlimited Server and PC, you can try the Unlimited Version.

Cherry · Staff Editor
Cherry is an editor of AOMEI Technology, she covers backup & restore, hard disk & partitions management, cloud files transfer, website & database backup and so on for AOMEI. She enjoys helping people find solutions to their problems. She loves traveling, cooking, reading and so on. She takes most of time with her family when she is not working.