Microsoft uses their product Windows to display advertisement to the user deeply integrated within the operating system, showing the company does not see the distribution of their operating system as their main core business but as a platform for making profit from ad revenue.
End users who expect to use the Windows operating system an effective tool for their everyday life may be easily annoyed and disappointing by the vendor’s practice.
source: https://www.theverge.com/2017/3/17/14956540/microsoft-windows-10-ads-taskbar-file-explorer
archived source: https://wellthissucks.xyz/2017/03/17/microsoft-is-infesting-windows-10-with-annoying-ads-archived-source/