I've never developed a "real" application for Windows, so I didn't know this off the top of my head, but it appears that compressed PNG format has been supporte

I've never developed a "real" application for Windows, so I didn't know this off the top of my head, but it appears that compressed PNG format has been supported for icons since Vista, which came out in like 2007. See: https://devblogs.microsoft.com/oldnewthing/?p=12473 https://devblogs.microsoft.com/oldnewthing/?p=12473