How to exclude Windows desktop from Google Ads


Per Google there are types, it does list “you can target specific operating
systems”:

About device targeting
For Display and Video campaigns, you can target specific device types, operating 
systems, device models, and ad inventory (spaces where publishers allow ads to run), 
as well as carriers and wireless networks. Some of these advanced mobile and tablet 
options aren’t available for other campaign types.

Computers: These are desktop or laptop devices with screens larger than 7" in 
diagonal. Selecting this option will give you access to all ad inventory that runs on 
computers.  

Mobile: These are hand-held devices that include a phone. 

Tablet: Tablets are mobile devices that don't necessarily include a phone.

TV screens: These are devices that stream TV content such as smart TVs, gaming 
consoles, and connected devices like Chromecast. This targeting option is only 
available for Display and Video campaigns.

Source: https://support.google.com/google-ads/answer/1722028?hl=en