Microsoft Office Click to Run: 7 Proven Fixes for High CPU

Written by: Kymakers Support Team · Reviewed by: Kymakers Technical Team
Last updated: July 2026 · Applies to: Microsoft Office 2016–2024, Microsoft 365 (Windows 10/11)
Difficulty: Beginner to Intermediate · Estimated time: 15–45 minutes

Microsoft Office Click to Run is the streaming and virtualisation technology Microsoft uses to install and update Office. You see it in Task Manager as OfficeClickToRun.exe, and its job is to keep Word, Excel, Outlook and the rest patched in the background.

Normally it’s lightweight. But it regularly spikes CPU and disk usage — and if that’s why you’re here, the first thing to know is that a spike during an update is normal and temporary. Give it 30 to 60 minutes before troubleshooting. If it’s still hammering your CPU after that, this guide covers seven proven fixes, plus an honest answer on whether disabling it is safe for your setup.

⚠️ First: check it’s actually Microsoft’s file

Malware sometimes imitates this process name. In Task Manager, right-click Microsoft Office Click to Run and choose Open file location. The genuine file sits in C:\Program Files\Common Files\Microsoft Shared\ClickToRun\. If it opens anywhere else, don’t follow the fixes below — run a full malware scan with Windows Security first.

Table of Contents

1. What Microsoft Office Click to Run actually does
2. Fix 1: Wait it out (seriously)
3. Fix 2: Run a Quick Repair
4. Fix 3: Run an Online Repair
5. Fix 4: Clear the Office cache
6. Fix 5: Update Office manually
7. Fix 6: Set the service to Manual
8. Fix 7: Disable it — and what you lose
9. Should you disable it? An honest answer
10. FAQ

What Microsoft Office Click to Run Actually Does

Microsoft Office Click to Run replaced the old MSI installer. Instead of downloading the entire suite before you can use anything, it streams the installation — you can start working in Word while the rest still installs. It also runs Office in a virtualised layer, which prevents conflicts with other software versions.

There are two processes people confuse:

• OfficeClickToRun.exe — the main background service. Always running.
• OfficeC2RClient.exe — appears during installs, repairs, and updates. Temporary.

If OfficeC2RClient.exe is the one using CPU, an update is almost certainly installing right now. That’s the process doing exactly what it’s designed to do, and it will stop on its own.

Fix 1: Wait It Out (Seriously)

This is the fix most guides skip, and it’s the correct answer more often than any other.

Microsoft Office Click to Run consumes real CPU when it’s downloading and applying an Office update in the background. That’s not a fault — it’s the update installing. Usage returns to normal when it finishes.

Give it 30 to 60 minutes before doing anything else. Check Task Manager again afterwards. If CPU has dropped back to near-zero, nothing was ever wrong. If it’s still high an hour later, or it’s high every single day, move to Fix 2.

Fix 2: Repair Microsoft Office Click to Run With Quick Repair

Corrupted Office files make Microsoft Office Click to Run work far harder than it should — retrying operations that keep failing.

1. Close every Office application.
2. Open Control Panel (set “View by” to Large icons) → Programs and Features.
3. Select your Microsoft Office or Microsoft 365 entry → click Change.
4. Choose Quick Repair → Repair.
5. Restart your PC.

Quick Repair works offline and takes a few minutes. It scans for corrupt files and fixes the common cases without touching your settings or files — often enough to settle Microsoft Office Click to Run down for good.

Fix 3: Run an Online Repair

If Quick Repair doesn’t resolve it, Online Repair is the thorough version.

Follow the same path (Control Panel → Programs and Features → your Office entry → Change), but choose Online Repair. This effectively reinstalls Office, downloading fresh files from Microsoft. It takes considerably longer and needs a stable internet connection.

Your documents aren’t touched, but you may need to sign in again afterwards. This resolves the majority of persistent Microsoft Office Click to Run problems that survive a Quick Repair.

Fix 4: Clear the Office Cache

A bloated cache causes the high disk usage variant of the Microsoft Office Click to Run problem, and it’s easy to clear.

1. Close all Office apps and stop the Click-to-Run service temporarily (see Fix 6 for how to reach it).
2. Press Windows + E and navigate to:
   C:\Users\<YourUsername>\AppData\Local\Microsoft\Office\
3. Clear the contents of the OfficeFileCache folder (and the Spw folder if present).
4. Restart the service and reopen Office.

Deleting cache contents is safe — Office rebuilds what it needs. Just don’t delete the folders themselves, only what’s inside them.

Fix 5: Update Office Manually

When an update download gets interrupted, Microsoft Office Click to Run can retry repeatedly, burning CPU each time. Completing the update manually breaks that loop.

1. Open any Office app (Word is fine).
2. Go to File → Account (or Office Account).
3. Click Update Options → Update Now.
4. Let it finish completely.

Also check you’re not on a metered connection (Settings → Network & Internet → your connection), and pause OneDrive sync while the update runs. Both interfere with updates completing cleanly, which is what causes the retry loop in the first place.

Fix 6: Set Microsoft Office Click to Run to Manual

This is the middle-ground option, and for most people it’s better than disabling outright.

1. Press Windows + R, type services.msc, press Enter.
2. Find Microsoft Office Click-to-Run Service.
3. Right-click → Properties.
4. Change Startup type to Manual → Apply → OK.

On Manual, the service stays off until an Office app needs it, then starts itself. You get no background CPU usage when Office is closed, but updates still work when you’re actually using Office. Many administrators prefer this setting, and it’s easily reversed by switching back to Automatic.

Fix 7: Disable It — and What You Lose

You can set the service to Disabled in the same Properties window, and stop it. Microsoft Office Click to Run will stay off.

But understand the trade-off before you do:

• No automatic updates — including security patches for Office. You’d need to update manually and remember to do it.
• Scheduled tasks restart it anyway. Microsoft creates scheduled tasks that relaunch the service roughly hourly. To keep it off you’d also need Task Scheduler → Microsoft → Office, and disable the tasks there (like “Office Automatic Updates”).
• On Microsoft 365, apps may eventually stop opening. A subscription needs to periodically verify its licence. Block that mechanism long enough and Office can refuse to run.

That last point is the important one, and it’s why the next section matters.

Should You Disable It? An Honest Answer

It depends entirely on what licence you have — and this distinction is rarely explained properly.

If you’re on Microsoft 365 (subscription): don’t disable it. Your Office apps need to check in periodically to confirm the subscription is active. Cutting off that mechanism risks apps refusing to open, and you lose security updates. Use Fix 6 (Manual) instead if background CPU bothers you.

If you have a perpetual licence (Office 2019, 2021, 2024): disabling is lower risk. A one-time-purchase licence doesn’t need ongoing subscription validation, so your apps keep working. But you still lose automatic security updates, so you’d need to run manual updates yourself — and honestly, Manual (Fix 6) gives you almost the same benefit without that responsibility.

The recommendation for nearly everyone: use Manual, not Disabled. You get the CPU savings without giving up patches. Disabling is for specific, deliberate cases — an offline machine, a locked-down kiosk, a system where you control updates centrally.

FAQ About Microsoft Office Click to Run

What is Microsoft Office Click to Run?
It’s the streaming and virtualisation technology Microsoft uses to install and update Office. It lets you start using Office before installation finishes, runs apps in an isolated layer to avoid conflicts, and applies updates in the background.

Why is Microsoft Office Click to Run using so much CPU?
Most often because an Office update is installing — that’s normal and temporary. Wait 30–60 minutes. If it stays high, corrupted Office files, a bloated cache, or an interrupted update stuck in a retry loop are the usual causes.

Is it safe to disable Microsoft Office Click to Run?
On a perpetual licence (2019, 2021, 2024), it’s relatively safe but costs you automatic security updates. On Microsoft 365, it’s risky — apps may eventually stop opening because the subscription can’t validate. Setting the service to Manual is the safer option for both.

Is OfficeClickToRun.exe a virus?
The genuine file is at C:\Program Files\Common Files\Microsoft Shared\ClickToRun\. Right-click the process in Task Manager and choose Open file location to check. If it’s anywhere else, run a full malware scan.

What’s the difference between OfficeClickToRun.exe and OfficeC2RClient.exe?
OfficeClickToRun.exe is the always-running background service. OfficeC2RClient.exe appears temporarily during installs, repairs, and updates. If the client executable is using CPU, an update is in progress.

Why does the service restart after I disable it?
Microsoft creates scheduled tasks that relaunch it roughly every hour. To keep it off, also disable the tasks under Task Scheduler → Microsoft → Office.

If Microsoft Office Click to Run’s constant background updating is what’s bothering you, it’s worth knowing the licence difference: a perpetual Office licence doesn’t need the ongoing subscription checks that make disabling risky on Microsoft 365. Kymakers supplies genuine one-time-purchase keys for Office 2024 Professional Plus, Office 2021 Professional Plus, and Office 2024 Home and Business — buy once, own it, no subscription. Our CD key MS Office buyer’s guide covers choosing the right version, and Office LTSC 2024 explained compares the editions.

Wait it out first. Repair if it persists. Set the service to Manual rather than Disabled — and keep your security updates.

Official reference: Repair an Office application — Microsoft Support