If you're seeing the following error while installing Microsoft Office:
We can't install
The following product(s) can't be installed at the same time:
O365HomePremRetail
it usually means that a pre-installed Microsoft 365 (Office) app is still installed on your PC and is preventing your new Office version from being installed. Removing the pre-installed Office app usually resolves the issue.
💡 Before You Begin
Before starting, make sure you have:
✅ Administrator access to your Windows PC
✅ All Microsoft Office applications closed
✅ Your Office installation file ready
Step 1 – Open Installed Apps
Click Start and open Settings.
Go to Apps.
Select Installed apps (or Apps & features on Windows 10).
Step 2 – Remove Microsoft Office Desktop Apps
Scroll through the list and look for any of the following:
Microsoft Office Desktop Apps
Microsoft 365
Microsoft 365 (Office)
Office 365
If you find one:
Click the three dots (⋯) next to it.
Select Uninstall.
Follow the prompts until it has been completely removed.
Important:
You only need to remove the pre-installed Microsoft 365 app that is causing the conflict. Do not uninstall your newly installed Office if it appears in the list.
Step 3 – Restart Your Computer
After the uninstall finishes:
Restart your PC.
Wait until Windows has fully loaded.
This ensures all Office components have been removed.
Step 4 – Install Office Again
Run your Office installer again.
The installation should now complete normally without displaying the O365HomePremRetail error.
Still Seeing the Error?
If the error still appears, there may be leftover Office components on your computer.
We recommend using Microsoft's official Office uninstall tool to completely remove all Office installations before installing Office again.
Microsoft Office Removal Tool
https://aka.ms/diag_officeuninstall
✅ Success
Once the conflicting Microsoft 365 app has been removed, your Office installation should complete successfully and you can activate Office using your purchased product key.