[chirp_users] Bf-888s

I am very new to radios and programming. I am trying to program a BF-888S for my business using your software. The radio was purchased a week ago along with Baofeng cable. I get an error message of "radio refused to enter programming mode". I have tried all the Baofeng models listed with similiar results on 2 different laptops. Any help wouldbe appreciated. Thanks