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How to Install and Configure an EA on MT4

Updated 1 September 2026 · 7 min read · PipTax education

If you want to install an EA on MT4, the process is mostly copy-paste-and-tick-a-box — but getting the settings wrong is how traders lose money without realising why. This guide walks through the full workflow: finding the right folder, attaching the EA, setting the inputs, testing it properly, and checking your broker won't quietly work against the strategy.

What You Need Before You Start

Before touching any files, make sure you have the basics in place:

• MT4 installed from your broker (Pepperstone and IG both offer their own MT4 downloads with slightly different server lists).
• The EA file itself — usually a .ex4 (compiled, ready to run) or .mq4 (source code) file, plus any .set files with recommended input settings.
• A demo account to test on first. Never install an unfamiliar EA straight onto a live account.
• Login details for the correct MT4 server matching your broker account type.

If the EA came with a PDF guide or a .set file, keep both handy — you'll need the recommended inputs later. Also check whether the EA needs any additional files, such as custom indicators, which install the same way but into a different folder.

Installing the EA File

This is the step most people get stuck on, usually because they drop the file in the wrong place.

1. Open MT4 and go to File > Open Data Folder. This opens the actual folder MT4 reads from — not your Program Files installation folder. 2. Navigate to MQL4 > Experts. 3. Copy your .ex4 or .mq4 file into that Experts folder. 4. If you have a custom indicator that the EA depends on, put it in MQL4 > Indicators instead. 5. Close MT4 completely and reopen it — a simple refresh in the Navigator window sometimes isn't enough. 6. In the Navigator panel (Ctrl+N if it's hidden), expand Expert Advisors and confirm your EA now appears in the list.

If it doesn't appear, double-check you saved the file directly in the Experts folder and not in a subfolder, and that the file extension wasn't accidentally changed by your browser or zip tool.

Attaching the EA to a Chart

Once the EA shows in the Navigator, it needs to be attached to the correct currency pair and timeframe — this matters because many EAs are built for one specific pair/timeframe combination.

• Drag the EA from the Navigator onto the chart it's designed for.
• A settings window will pop up automatically — don't click OK yet.
• Check the chart's timeframe matches what the EA's documentation specifies (e.g. M15, H1).
• Confirm the symbol name matches exactly, especially if your broker uses suffixes (like EURUSD.a).

Once attached, you'll see a smiley face icon in the top-right corner of the chart. A grey/sad face means the EA is not actively trading; a green smiley face means it's live and running.

Configuring EA Settings and Inputs

This is where most of the real decision-making happens, and it's where blindly using default settings can cause trouble.

In the pop-up window when attaching the EA:

• Common tab — tick "Allow live trading" (this is separate from the global AutoTrading toggle).
• Inputs tab — this lists every adjustable parameter: lot size, stop loss, take profit, magic number, risk percentage, trading hours, and so on.
• Load a .set file if the EA provider supplied one, rather than guessing values yourself.

Key inputs worth double-checking every time:

| Setting | Why it matters | |---|---| | Lot size / risk % | Controls position size and account risk exposure | | Magic number | Stops the EA's trades clashing with other EAs on the same account | | Max spread filter | Prevents trades during unusually wide spread conditions | | Trading session hours | Some EAs are built for specific market sessions only | | Slippage tolerance | Affects how orders behave in fast-moving markets |

Don't run an EA with settings you don't understand — read the documentation or ask the developer before going live.

Enabling AutoTrading Correctly

An EA can be perfectly installed and configured and still do nothing if AutoTrading isn't enabled — this trips up almost everyone at least once.

There are two separate switches that both need to be on:

1. The global AutoTrading button on the main MT4 toolbar (it should show green, not red). 2. The "Allow live trading" tick box in the EA's own Common tab settings, applied per chart.

If either is off, the EA sits there doing nothing even though it looks attached. Also check:

• Your broker allows automated trading on that account type.
• Your internet connection and platform stay running — MT4 must remain open for the EA to work, unless it's on a VPS.
• The Experts tab at the bottom of MT4 for any error messages or rejected trade logs.

Backtesting and Demo Testing Before Going Live

Never skip this step just because the EA "looked good" in a marketing video.

• Open the Strategy Tester (View > Strategy Tester or Ctrl+R).
• Select the EA, symbol, timeframe and date range.
• Set the model to "Every tick" for the most realistic simulation available in MT4.
• Add a realistic spread value rather than leaving it at zero — this alone can flatter results dramatically.
• Run it, then study the drawdown and equity curve, not just the net profit figure.

After backtesting, run the EA on a demo account for several weeks in real market conditions before committing real capital. Compare live demo results against the backtest — large gaps often point to unrealistic assumptions about spread, slippage or execution speed.

Checking Broker Costs and Execution

An EA's real-world results depend heavily on the account it's running on, not just the strategy logic.

• Spreads and commissions eat directly into an EA's edge, especially for high-frequency or scalping-style strategies.
• Execution model (market maker vs ECN/STP) can change fill quality and slippage.
• Swap rates matter for EAs that hold trades overnight — check current rates before running anything long-term.

Rather than guessing, run your account type and instrument through PipTax's [cost tool](/audit.html) to see live spread and commission comparisons, and browse [broker profiles](/brokers/index.html) for details on execution type and account structures across providers like Pepperstone and IG.

Conclusion

Learning to install an EA on MT4 is straightforward mechanically — copy the file, attach it, tick AutoTrading — but the real work is in configuring the inputs correctly, testing honestly, and understanding how your specific broker's costs and execution affect the outcome. Treat backtests as a starting filter, not proof, and always demo-test before going live. For more structured lessons on automated trading and platform setup, visit the [PipTax School](/school/index.html), and see [our methodology](/methodology.html) for how we assess broker execution quality.

Keep going: Audit Index Index Methodology