Finally got around to fixing my old PC desktop. Knew about the problem for a while, but was too lazy to get around to fixing it. But sorted it out with help of Perplexity, it did the researching for me, found a couple of free options, told me which one was more likely to solve the issue, gave me step by step instructions to try out. Chose the slightly more risky option, repartitioning the hard disk without backup. Fixed it. Now running Windows 11 latest update.
If you have an old Dell Inspiron, you might struggle to update the system to run Windows 11 latest system update. The main cause is that the EFI System Partition is only 100MB, which is not enough for installing the update. There are no tools from Dell to solve this. And you have to get your hands dirty to repartition the hard disk to extend the drive. You can do it with a free app, MiniTool Partition Wizard.
Here are the steps.
Step 0: Prerequisites & Precautions
Before starting, ensure:
10+ GB free space in your C: drive (Windows partition). Check this: Right-click C: → Properties → Note the "Free space" amount.
BitLocker is OFF. If enabled, disable it first (Settings → Privacy & Security → Device encryption → Off).
No power loss during the operation — use a UPS or laptop with full battery.
Backup important data to external drive (optional but recommended).
Check your OS partition free space:
Open File Explorer
Right-click C: drive → Properties
Note the Free space value (must be 10+ GB)
Step 1: Download & Install MiniTool Partition Wizard (Free)
Go to https://www.partitionwizard.com/free-partition-manager.html
Click Download to get the free version
Run the installer. Important: During installation, select "Free Edition" when prompted (not the trial), then click Next33
Complete the installation and launch the program
You'll see the main interface showing your disk layout with all partitions listed.
Step 2: Identify Your Partitions
When you open MiniTool Partition Wizard, you'll see a disk map at the top and a partition list below. Locate:
EFI System Partition (100 MB, marked "EFI" or "ESP")
Microsoft Reserved Partition (MSR) (16 MB, marked "Other" or "MSR")
C: drive (Windows OS partition)
Recovery Partition (if present, optional)
Important: In some cases, there's a 128MB "Other" partition between EFI and C: drive. If present, you must delete it first—it blocks EFI expansion.34
Step 3: Delete the Microsoft Reserved Partition (MSR)
The MSR partition cannot be resized or moved by partition software—it must be deleted and later recreated via diskpart.35
In MiniTool's partition list, right-click the "MSR" or "Other" partition (16 MB, between EFI and Windows)
Select Delete Partition from the menu
Click OK to confirm
Do NOT click Apply yet—wait until all operations are queued
Result: You'll see 16 MB of unallocated space where MSR was.
Step 4: Shrink the Windows (C:) Partition
Now you need to shrink your C: drive to create space for the expanded EFI partition. You'll shrink it by 2.2 GB total: 1.5 GB for the enlarged EFI partition, and 0.7 GB to recreate the MSR partition later.
Right-click your C: drive (Windows partition, usually labeled "C" or "SYSTEM")
Select Move/Resize Partition
In the dialog that appears:
Current size will show (e.g., 237.83 GB)
Reduce it by 2.2 GB (e.g., if 237.83 GB, set to 235.63 GB)
Observe that "Unallocated Space After" increases to 2.20 GB[^2_5]
Adjust the slider so "Unallocated Space After" is set to 1.5 GB (this leaves 0.7 GB before the EFI partition for MSR recreation)
Click OK
Do NOT click Apply yet
Step 5: Expand the EFI System Partition
Now you'll take that unallocated space and add it to the EFI partition.
Right-click the EFI System Partition (100 MB, at the start of your disk)
Select Move/Resize Partition
In the dialog:
Current size shows 100 MB
Set Partition Size to 650 MB (this is 550 MB of expansion)[^2_5]
The unallocated space should now appear to the right of the EFI partition
Click OK
Do NOT click Apply yet
Your changes are now queued. MiniTool shows a list of pending operations at the bottom.
Step 6: (Optional) Expand Recovery Partition
If you have a Recovery partition and want to give it more space (recommended for future Windows updates), repeat the process:
Right-click the Recovery partition (usually ~600 MB)
Select Move/Resize Partition
Increase its size to 2 GB using the remaining unallocated space[^2_5]
Click OK
If you skip this, your remaining ~0.7 GB of unallocated space will sit unused (harmless).
Step 7: Apply All Changes
Once all partition operations are queued:
Click the Apply button (upper-left corner of MiniTool window)
A confirmation dialog appears: "Apply Pending Changes?"
Click Yes
MiniTool will execute the operations and ask to Restart Now
Click Restart Now
Your computer will reboot and the partition operations will execute. This takes 5–10 minutes. Do NOT interrupt the process.
You'll see a progress bar on boot. Once complete, your system returns to Windows.
Step 8: Verify the Changes
Once rebooted:
Open MiniTool Partition Wizard again
Verify that:
EFI partition is now ~650 MB (was 100 MB)
C: drive is shrunk by 2.2 GB
Unallocated space remains (~0.7 GB)
Try the Windows 11 25H2 upgrade again—it should now succeed
Leave a Comment