I get no indication when my cursor is on the side of a window or a corner of a window, meaning I'm correctly positioned to resize the windows. On other installations of Zorin I see them, but not on my latest install. Sometimes I can grab the corner and resize even without the indication, but not always.
Also, is there a way to make the change the minimize and maximize buttons (upper right of windows) look like the MS Windows buttons (and add in the windowed option, giving minimize, windowed, and maximized)?
If you don't see the cursor change to a double-headed arrow at the window edges, it's usually because the "invisible" border for grabbing is too thin or the cursor theme is glitching.
Something to try:
Zorin Appearance > Themes > Other (or Cursor depending on your Zorin version).
Temporarily switch to a different cursor (like "Adwaita" or "Zorin Blue") to see if the icons return.
As for the "Windowed" (Restore) button, in Linux, the "Maximize" button acts as a toggle between maximized and windowed. If the window is already maximized, clicking the maximize button again "restores" it to a windowed state.* There isn't usually a separate third button for this, as the one button handles both states. *(Actually Windows does this too...)
Which Zorin version do you use? Are you on Zorin Lite? If yes:
In Zorin Lite the border to resize the window is only 1px wide with the default Zorin theme. It is difficult to hit this small line. You can click on the arrow on the left side of the top of the window and select resize to change the size of the window, or press left Alt+ right mouse key and then drag the window. Another option is to download another gtk theme with wider borders.
Could You add if You use Zorin 17 or 18 and if it is Pro, Core or Lite please?
Do You use one of the default Zorin Themes or a Third-Party Theme?
They should be like this on default. Here would be my Question, too: Are You using one of the default Zorin Themes or a Third-Party Theme? Coulc You maybe add a Screenshot?
You can ignore my second question as was answered above (it already works like Windows does). I think I must have been drinking when I posted that question