According to this new report upgrading to Windows 11 makes your computer slow

 

Microsoft is making significant efforts to persuade the majority of Windows 10 users to transition to the new Windows 11 before October 14. While Microsoft promotes Windows 11 as the best operating system currently available, offering superior optimization, security, and performance, some evaluation benchmarks seem to disagree.

The data published by PassMark, a benchmarking organization that recently released its latest findings on Windows-based PC performance in 2025, is quite intriguing.

For the first time in history, we are witnessing a decline in Windows operating system performance on PCs. This raises speculation about whether the shift from Windows 10 to Windows 11 is not entirely positive in terms of performance.

Several factors could be contributing to this issue, including the increasing number of unnecessary programs in the latest Windows 11 versions compared to previous years. Another noteworthy finding is that most computers do not exceed eight CPU cores. This suggests that processors with a higher core count are not particularly beneficial.

It remains unclear whether upgrading from Windows 10 to Windows 11 directly affects PC performance. However, Microsoft still has a long way to go to convince many users to update before October 14.