Hi Guys
can you please tell me how I can establish which USB standard my PC is running.

You might be able to detect via Device Manager: Start/Run/ devmgmt.msc
If there is anything like Ultra or somesuch listed under USB you probably have USB 2.

Trial & error is to insert USB 2 hardware & watch for messages/ errors.

Most devices will revert to 1.1 if able.

Another method would be to check the manual or post/ search the exact make & model of the computer or motherboard.

thanks for your prompt response, will try what you suggest.