You should check your manafactures website or the manual of your computer for further details stating whether it is HDCP compliant or not.
Most older laptops/Monitors are not HDCP compliant, if you're using vista or XP, it won't support it. The best way to find out is to check the model number of the display and the manafacturer of the display. Also, your graphic card has to support it as well. Or you're just gonna get errors.