Even after installation, axes may drift.
Since there is no "official" UCOM portal today, the driver is typically hosted on community driver archives. You should look for the "USB Gamepad with Vibration" driver package, which is the standard software for the chipset inside the UC-JS704S2. ucom uc js704s2 usb joystick driver win 7 download link
Disclaimer: Always ensure you are downloading drivers from a trusted source to protect your system from malware. Even after installation, axes may drift
After installing the driver, restart your computer and test the joystick to ensure it's working correctly: Even after installation