Microsoft Confirms Outlook Bug Causing 50% CPU Spikes While Typing

BigGo Editorial Team
Microsoft Confirms Outlook Bug Causing 50% CPU Spikes While Typing

Microsoft's classic Outlook application is experiencing a significant performance issue that's causing headaches for users across multiple update channels. The bug, which manifests as severe CPU spikes when simply typing emails, adds to a growing list of recent Microsoft service disruptions affecting workplace productivity tools.

The Microsoft Outlook interface, highlighting the platform affected by the performance issues described
The Microsoft Outlook interface, highlighting the platform affected by the performance issues described

The Bug's Impact on System Performance

Microsoft has officially acknowledged a serious performance issue in the classic Outlook application that causes CPU usage to spike dramatically—between 30% and 50%—when users are simply typing emails. This excessive CPU consumption not only slows down Outlook itself but also impacts other applications running simultaneously on affected systems. In extreme cases, users with high-performance processors like the i9-14900HX have reported their CPUs reaching temperatures as high as 95 degrees Celsius when simply opening the New Message window. The issue also leads to increased power consumption, which is particularly problematic for laptop users who depend on battery life for productivity away from power outlets.

Affected Versions and Distribution

The problem specifically impacts users running Version 2406 Build 17726.20126 or newer, which was released in June 2024. This bug has been confirmed across multiple update channels, including the Current Channel, Monthly Enterprise Channel, and Insider Channels. Given the widespread distribution across these major release channels, a substantial number of enterprise and individual users are likely experiencing degraded performance. The issue appears to have been present since at least November 2023, based on forum posts referenced in Microsoft's support documentation, though the company has only recently provided official acknowledgment.

No Permanent Fix Yet Available

Microsoft has stated that its Outlook team is actively investigating the issue, but no permanent resolution has been developed at this time. This lack of an immediate fix is particularly frustrating for organizations that rely heavily on Outlook for daily communications, as the performance degradation directly impacts workplace efficiency. The timing is especially unfortunate as it follows closely behind other recent Microsoft service disruptions, including file-sharing difficulties in Microsoft Teams and a bug that prevented users from reverting to older versions of Outlook.

Temporary Workaround Solution

While Microsoft works on a permanent solution, the company has offered a workaround for affected users. The recommended approach involves switching to the Semi-Annual Channel, where this issue has not been observed. Organizations can implement this change through the Office Deployment Tool, following Microsoft's published guidance. For individual users, Microsoft provides a simpler registry modification method that can be implemented by running a specific command in an administrator Command Prompt:

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

After adding this registry key, users need to navigate to File > Office Account > Update Options > Update Now within Outlook to complete the transition to the Semi-Annual Channel. While not ideal, this workaround should provide relief until Microsoft develops and deploys a proper fix for the underlying issue.

Broader Context of Recent Microsoft Service Issues

This Outlook performance bug represents just one in a series of recent technical challenges facing Microsoft's productivity suite. Earlier issues with Microsoft Teams file sharing and problems with Outlook version rollbacks have created a pattern of disruptions that impact enterprise workflows. These recurring issues raise questions about quality control and testing procedures for Microsoft's productivity software updates, particularly as organizations increasingly depend on these tools for daily operations in hybrid and remote work environments.