It's a bad day at the office for Microsoft. Just recently, we reported that people are experiencing difficulties while sharing files in Microsoft Teams, causing major disruptions in workflows and impacting overall enterprise productivity. Now, it appears that the classic Outlook app is causing headaches for customers too, which is yet another inconvenience too soon for users who were impacted earlier by a bug that left them unable to revert to the old version of the mail app.

Just typing in Outlook may be spiking your CPU usage

In a support document, Microsoft has detailed an issue that is causing CPU usage to spike by 30% to 50%, along with increased power consumption, if you're typing in the classic Outlook app. The Redmond tech firm says that this issue is observable if you monitor the CPU utilization of the app in Task Manager. The problem is currently impacting customers using Version 2406 Build 17726.20126+ in the Current Channel, Monthly Enterprise Channel, and Insider Channels. Microsoft hasn't specified any other criteria for this issue, but given that it's affecting major release channels, a large number of customers are likely impacted.

No resolution available just yet

While this bug is clearly problematic, especially since it will impact the performance of other applications simultaneously running on your PC too, Microsoft doesn't have a resolution just yet. For the time being, it has requested customers to resort to a workaround, which involves switching to the Semi Annual Channel, where this issue has not been reported yet.

Customers can change their channels through the Office Deployment Tool and by leveraging the associated guidance here. Alternatively, they can do the same via modifying their registry keys by opening Command Prompt with admin privileges, and then running the command:

reg add HKLM\Software\Policies\Microsoft\office\16.0\common\officeupdate /v updatebranch /t REG_SZ /d SemiAnnual

Once this is done, they should open the Office app and navigating to File > Office Account > Update Options > Update Now. Interestingly, Microsoft has also recommended customers to check out this relatively old thread from November 2024, where users have reported a similar issue. At that time, the firm asked the initiator of the forum thread to reach out to its technical support team, so it's unlikely that you'll come across a firm fix. As such, Microsoft has only asked customers to refer to the thread for "insights" as its team works on a concrete resolution.