With respect, you're missing the point - the start menu width does not change with screen width, so on a smaller screen the start menu takes up more space.
You're comparing a ~800px-wide screen with a ~1400px wide screen - obviously the narrower screen is going to lose more to the start menu than the wider screen, even when the menu itself is exactly the same pixel size in both screens.
> here’s a smaller screenshot of Vista in English: https://betawiki.net/images/3/35/WindowsVista-6.0.6002.18005...
That's still much, much larger than the polish version you supplied. Why not show images of the polish version and the english version with the same resolution?
TBH, I get very skeptical when doctored evidence is produced in support of an argument. Your argument might have been better received had you produced no evidence at all rather than misleading evidence.