Unfortunately the only way to get around this issue is to switch back from Software to the default renderer. This can be done by switching to windowed mode.
To do this, right-click the game's shortcut, go to Properties, and edit the Target field. You should add this parameter at the end of the line:
By default, the entire line would then look like this:
"C:\Program Files (x86)\GOG.com\SWAT 3\game\swat.exe" -window.