Two-phase operation: ① expand virtual disk in VMware → ② extend C: partition inside Windows guest. This guide uses IM-Magic Partition Resizer (free) to safely move partitions and grow your system drive. This free tool can add unallocated space to any partition without losing data.
⏳ Before you start:
Backup the VM (snapshot or full copy). Safety first.
Power off the virtual machine.
Remove all snapshots (otherwise the Expand button is greyed out).
Video: How to expand VMware disk and add space to any drive like C
1️⃣ Phase 1 – expand virtual disk (VMDK) in VMware
This increases the maximum size of the virtual disk. The partition inside Windows isn’t changed yet.
VMware Workstation / Player: Edit VM settings → Hardware → Hard Disk → click Expand → enter new size.
VMware ESXi / vSphere: Edit Settings → select hard disk → increase size. Or use vmkfstools -X.
✅ After this step, the new space appears as “Unallocated” inside the guest OS.
2️⃣ Phase 2 – extend the C: drive using IM-Magic Partition Resizer
Launch the tool inside the VM. You’ll see a visual map of partitions. The key: unallocated space must be directly to the right of C:. If other partitions (System Reserved, D:, Recovery) are in between, we move them.
Why not Windows Disk Management? It cannot move partitions — if a partition sits between C: and unallocated, “Extend Volume” stays greyed out. IM-Magic Partition Resizer moves partitions safely.
💡 General rule: right-click a partition → Resize/Move → drag the whole partition left/right to reposition it. Then extend C: into the freed unallocated space. Always click “Apply” to commit.
Or you may click APPLY in the end to proceed all previous changes. It won't start to change until you click APPLY and confirm YES.
common A System Reserved (or Recovery) partition blocks C: from the new space.
Move D: to the right – right-click D: → Resize/Move → drag the entire D: partition to the right, and then the Unallocated space will be positioned to the left of the D: drive. Click OK.
Move System Reserved to the right – right-click System Reserved → Resize/Move → drag the whole partition to the right. Now Unallocated is adjacent to C:.
Extend C: – right-click C: → Resize/Move → drag the right border of C: into the Unallocated space. Click OK.
Apply – click the “Apply” button (bottom right) and OK to execute all changes. Reboot if prompted. (It won't start to change until you click APPLY and confirm OK)
✅ C: drive now uses the newly added space — data intact.
📌 Scenario B: C: | D: | Unallocated
Simpler layout — no system partitions in between.
Move D: to the right – right-click D: → Resize/Move → drag the entire D: partition to the right, so it sits beside Unallocated at its right. This leaves unallocated space between C: and D:.
Extend C: – right-click C: → Resize/Move → drag its right border into the unallocated space to absorb it. Click OK.
Apply – click “Apply” and OK to commit. Done. (It won't start to change until you click APPLY and confirm OK)
Alternative: Shrink D: from its left side, move it right, then expand C: — IM-Magic handles it all.
🔧 Troubleshooting & quick tips
“Expand” greyed out in VMware? VM must be powered off and no snapshots.
“Apply” triggers a reboot? Normal when modifying system partitions (EFI, System Reserved). Let it reboot — changes apply safely.
Disk Management still shows old size? Refresh or reopen the tool — the expansion is already done.
Worried about data? IM-Magic Partition Resizer is reliable, but a backup is always recommended before any disk operation.
📝 Final checklist
☑️ VM backed up
☑️ VM powered off, snapshots removed
☑️ Virtual disk expanded in VMware
☑️ Powered on VM, launched IM-Magic Partition Resizer
☑️ Moved blocking partitions (if any) so Unallocated is right next to C:
☑️ Extended C: drive
☑️ Clicked “Apply” — done, no data loss
✔️ This guide gives you the direct path: expand VMware disk, move partitions with IM-Magic Partition Resizer, extend C: — all without losing a single file.