Microsoft’s December 2025 update, released to improve security and stability, has unexpectedly turned into a performance nightmare for some users. Following the cumulative update coded KB5072033, many users are reporting that their computers are running slower than before and that system resources are being unnecessarily consumed.

Source of the Problem: AppXSVC and “Automatic” Startup

At the heart of the performance drop is the AppX Delivery Service (AppXSVC), responsible for installing and updating Microsoft Store applications (Calculator, Photos, etc.).

Previous Setup: Before the update, this service was in “Manual” mode; meaning it only started when installing or updating an application.

New Setup: With KB5072033, Microsoft switched this service to “Automatic” startup mode. This causes the service to start as soon as the computer boots up and remain constantly active in the background, increasing CPU, memory, and disk usage.

This change is particularly noticeable on systems with limited hardware resources (4-8 GB RAM or older processors). While the operating system allocates resources to this service in the background, the performance required for applications and games opened by users is reduced.

Not only home users, but also IT administrators are complaining about this situation. On managed systems, the constant starting and stopping of AppXSVC has led monitoring tools like Zabbix to generate thousands of false alarms such as “service crashed” or “constantly restarting.” IT professionals are forced to manually intervene to cope with this notification clutter.

While Microsoft defends this change as being to “increase reliability in certain scenarios,” there are a few workarounds for users who don’t want to sacrifice performance:

• Returning the Service to Manual Mode: You can set the service to run only when needed again by running Command Prompt (CMD) as administrator and typing the command sc config AppXSVC start= demand. Registry Editing: More advanced users can revert the startup type to its previous state by relinquishing authority through the registry, but Microsoft warns that such system modifications could break Store applications.