Look for numbers like 243 (not “243AT” – this may be a typo for a Singer model like Singer 2250 or Singer 14T968DC ).
or a sticker on the bottom of the laptop with a "Model Code"? singer+sinx+243at+laptop+drivers+free+download+high+quality
If you are installing drivers on a modern Windows 10/11 system: Look for numbers like 243 (not “243AT” –