System Workbench for STM32

Hi,

I was trying to flash code into the board for the first time I have installed stlink server and drivers also but still I am getting this error

Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : clock speed 8000 kHz
Error: libusb_get_device_list() failed with LIBUSB_ERROR_OTHER
Error: open failed (no matching adapter found)
in procedure 'init'
in procedure 'ocd_bouncer

Can anyone help??

Thanks in advance