Expert advisor use?

Hello,

At first i did a search but didnt find anything. So, i know how to install an expert adivsor (for example the firebird ea) but when i try to backtest myself with the same datas i end mostly up in a loss, whereas the author makes a profit. This is almost at every ea. i always get another results. Could you e.g explain how to exactly set up the firebird ea, so that i get the same results?
I also read the metatrader help file, but didnt help anything.
I hope iam not the only person, who has this problem.
Thank you - mike

Backtesting is not very reliable...forward testing on a demo for some weeks is the way to go.

Though backtesting can be made more accurate if one uses good data, accurate enough to determine winning strategies from losing ones.
Backtesting can also be used to optimize EA parameters.

nevertheless, could someone help me?

I am not familiar with the firebird? Most ea's I steer clear from. Too often they are written with a specific set of parameters in the market. When those parameters change in the real world ea's often fail to produce. Have you thought about learning how to spot when the parameters are ripe for your ea to work? It does take some research. But you will find that it can reap you more success than not. Some one else mentioned to avoid back testing, I agree with that testing forward in a demo really allows you the flexibility to learn and recognize when the markets are right for the particular ea in use. I hope this was helpful. FYI I use the Norwood Stop it is very flexible.