That "OBDII to USB" cable is not just a cable with wires in it - it is an interface converter with electronics that translate between the OBDII communication protocols and the USB communication protocols - it needs specific software for the laptop to be able to see it and communicate with it, this "driver" software needs to be matched to the laptop operating system and also whatever interface chips the cable manufacturer used.
Whoever made/supplied the cable should have provided software with it, maybe a CD, but at the very least a sheet of paper telling you what works and where to download it from.
There are quite a few "cheap chinese" copies of product from reputable manufacturers - for example the ELM327 chip - we don't know what's in your cable.
Do a Google search for free obd2 software - you'll find lots of links - which may or may not work - hence the suggestion to use what the manufacturer recommends.
my cable is off an SCT programmer but it will not read my Suzuki codes
it may no have any chip in it
so what I am looking for is a free obd2 diagnostic readerprogram to put into my laptop so I can read the obd2 codes from my 2000 grand vitara
I am hoping someone on this forum has done that an can make a recommendation
I'm going to suggest you read my previous post again - there is NO way to wire a J1962 OBD connector to a USB connector on a computer and get them to communicate without electronics in between. That would be the equivalent of holding the two wires of a telephone line, one in either hand, and making a phone call - your brain doesn't "speak" electrical signals - just as you need a telephone to convert the electrical signals to audio that your ears can hear and your brain understand, you need an OBD interface for your laptop to be able to talk to the vehicle's ECU.
The SCT cable you have may be a proprietary cable rather than an OBD interface, only SCT will know that.
If you want software to try, I've already suggested you do a google search, you'll find lots of links to free software, which like I said may or may not work.