Fix COMADMIN_E_INVALID_PARTITION (0X8011080B) on Windows Server

1. Corrupt or Missing COM+ Partition Objects – The Most Common Cause

The culprit here is almost always a corrupted COM+ partition entry in the registry or WMI repository. I've seen this on Windows Server 2019 and 2022 after a failed backup or disk resize. The error pops up when COM+ tries to enumerate partitions but finds an object that doesn't match the physical disk layout.

Fix: Reset the COM+ Partition Database

1. Open Component Services (dcomcnfg).
2. Navigate to Console Root > Component Services > Computers > My Computer.
3. Right-click COM+ Applications and select Properties.
4. Go to the Advanced tab. Click Restore Defaults for partition settings.
5. Stop and restart the COM+ System Application service in services.msc.
6. Run this command to re-register COM+:

regsvr32.exe /s combase.dll
regsvr32.exe /s comsvcs.dll

That fixes about 70% of cases. Don't bother reinstalling the COM+ role — it rarely helps.

2. Disk Partition Table Corruption – The VSS Writer Connection

Another common trigger is a Volume Shadow Copy (VSS) writer failing because of an inconsistent partition table. You'll see this after you've resized a partition with third-party tools or after a disk failure.

Fix: Check and Repair the Partition Table with Diskpart

1. Open an elevated command prompt.
2. Run diskpart.
3. List disks and select the problematic one:

list disk
select disk 0
list partition

If you see a disk marked as GPT but the partitions look like MBR (or vice versa), that's your problem. Convert it cleanly:

clean
convert gpt
create partition efi size=100
format quick fs=fat32
create partition msr size=128
create partition primary
format quick fs=ntfs
assign letter=C

Warning: clean wipes everything. Back up data first. If the disk has data, use chkdsk /f on the volume instead.

3. COM+ Catalog Database Corruption – The Registry Hive

Less common but nasty: the COM+ catalog registry hive (HKLM\SOFTWARE\Microsoft\COM3\) gets corrupted after a bad registry backup restore or a failed update. You'll get error 0X8011080B when launching any COM+ application.

Fix: Rebuild the COM+ Catalog

1. Backup the current hive: reg export "HKLM\SOFTWARE\Microsoft\COM3" com3_backup.reg
2. Stop COM+ services:

net stop COMSysApp
net stop EventSystem

3. Delete the registry key (yes, delete it):

reg delete "HKLM\SOFTWARE\Microsoft\COM3" /f

4. Recreate the catalog by running:

comadmin.exe /rebuildcatalog

That command is undocumented but works on Server 2016 and later. It rebuilds the entire COM+ catalog from scratch. You'll lose any custom COM+ applications, so export them first if needed.

Quick-Reference Summary Table

Start with the first fix. It's the easiest and most effective. If that doesn't clear it, move to the partition table check. The registry rebuild is your last resort — only do it if you're comfortable with regedit surgery.