Forex demo download
The main problem here is that many brokers severely limit the amount of demo trading that you can do. Some brokers allow you to keep a demo account open for only 72 hours before forcing you to make a decision on whether you are going to trade with real money or not.
While 72 hours is enough time to master the platforms software, it is not enough time to master a given strategy. But its a necessary step on the way to becoming one. You should never invest money that you cannot afford to lose.