Windows is not usable on a CRT because 1024x768 looks terrible AND Windows is unusable with less than that resolution.
1024x768 looks fine on a CRT, and any resolution that's not native on an LCD will look better on a CRT. I'm not really sure what you're getting at here... I agree, you don't wanna go less than that, but my CRT here is quite happily displaying a crisp, bright, contrastful Windows desktop at 1600x1200. My CRT at home performs similarly with Windows, Linux, And AmigaOS 3.9 and 4.1 - all at 1600x1200.
CRTs have round pixels and scanlines, LCDs have neither of those attributes so you need at least 1280x1024 LCD to get decent scanline effect anyway.
Indeed, to emulate the scanlines you need a high vertical resolution - at least twice that of the image you want to display.
