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How to Install Office 2021 Professional Plus: A Step-by-Step Guide

SimplySolutions Team
SimplySolutions Team
January 15, 2026
5 min read
How to Install Office 2021 Professional Plus: A Step-by-Step Guide

Why Choose Office 2021 Professional Plus?

Microsoft Office 2021 Professional Plus is the ultimate productivity suite for businesses and power users. Unlike Microsoft 365, it is a one-time purchase with no monthly fees. This guide will help you install and activate your genuine license key from SimplySolutions.

Prerequisites

Before you begin, ensure you have:

  1. A valid license key (purchased from SimplySolutions)
  2. Stable internet connection
  3. Windows 10 or Windows 11 installed
  4. Removed any older versions of Office

Step 1: Uninstall Previous Versions

To avoid conflicts, it is crucial to uninstall any existing Office installations.

  1. Go to Settings > Apps > Installed Apps.
  2. Search for "Office" or "Microsoft 365".
  3. Click the three dots and select Uninstall.
  4. Restart your computer.

Step 2: Download the Installer

Always download from the official Microsoft CDN.

Step 3: Installation

  1. Locate the downloaded .img or .iso file.
  2. Right-click and select Mount (or double-click it).
  3. Open the folder and find Setup.exe.
  4. Double-click Setup.exe to start the installation.
  5. Wait for the process to complete (you'll see "You're all set! Office is installed now").

Step 4: Activation

  1. Open any Office app, like Word or Excel.
  2. You will be prompted to "Enter your product key".
  3. Copy the license key you received from SimplySolutions via email.
  4. Paste it into the box and click Activate Office.
  5. Accept the license agreement.

Troubleshooting

  • "Key already used": Ensure you typed it correctly. Contact support if issues persist.
  • Telephone Activation: If online activation fails, select "I want to activate the software by telephone" and follow the prompts.

Need a genuine key? Buy Office 2021 Professional Plus here.

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