Once you know the chipset (e.g., Realtek RTL8187 or Ralink RT3070, which were highly common in Kinamax high-power adapters), go directly to the official Realtek or MediaTek websites to download the Windows 7 driver securely.
Because Kinamax is not a mainstream consumer brand (unlike Epson or HP), official drivers are not hosted on major download portals like Microsoft Update or major OEM sites. Instead, drivers are distributed via niche POS driver aggregators, regional Kinamax resellers, or generic ESC/POS compatibility layers. kinamax ts 9900 driver download windows 7 new