I don't know your computer components. If the motherboard brand of your computer is MSI, only PWM fans can be adjusted. A brand like ASUS, any fan non-PWM and PWM can be adjusted. If your computer's warranty has expired, you can try carefully open the computer and inspect the cables for the fans. If it is 3 or 2 wire fans, then it is a non-PWM. If it is 4 pin, then it is probably a PWM. If your computer is within warranty period contact ibuypower.
You can download a portable version (usually its a zip file) of CPU-Z. Select the Mainboard tab in CPU-Z and post the model that is listed in the Motherboard category/frame.