MT4 Built Version 600
Terminal: Changed the terminal data structure and storage location - now, the data of each installed terminal is stored in a separate terminal data folder.
Since the release of MetaTrader 4 platform in 2005, selected terminal installation directory was also the place where all data necessary for work (terminal logs, templates, profiles, quotes, etc.) has been stored. But with the release of Windows Vista in 2008, all Microsoft operating systems implement serious limitations of user privileges in order to protect them against malicious programs and to prevent applications under one user account to change or damage the same program's data necessary for another user account.
Starting with Windows Vista, User Account Control (UAC) mechanism was introduced. The main idea of implementing the mechanism is that the application's unchangeable data stored in the installation directory should be separated from user's data modified by this application during its operation. Thus, all data of each user should be stored in a separate folder. You can find more information about UAC in Windows help or the Wikipedia article.
In the new version, all data of a certain user working with MetaTrader 4 terminal from a separate installation directory are stored in the terminal data folder. This folder can be found on a system disk (a disk with installed Windows operating system) along the following path
- С: - name of a system disk;
- User_account_name - user's account for working in Windows;
- Instance_id - unique name of the folder where the entire user's data for working with a certain copy of MetaTrader 4 terminal is stored.
"Open Data Folder" command has been added to File menu of the terminal for searching and opening the data folder.
The root of each terminal data folder also contains origin.txt file where you can find the path to the installation folder of the terminal this data refers to. This allows users to reversely match each terminal data folder with a certain terminal installation directory, for example, in case when several copies of MetaTrader 4 terminal are installed by a user. This type of working with the terminal when the data folder is separated from the installation one is the main mode and highly recommended for security reasons.
The terminal can also be launched in the so-called Portable mode (as in previous MetaTrader 4 builds). In that mode, the data is stored and recorded in the installation folder. To do this, use "/portable" key. For more convenience, you can create an additional terminal launch shortcut with the appropriate name on your desktop and add the key directly to the shortcut:
When updating the old terminal version, existing user data is copied to the new location in two cases:
- installation directory is different from the data one;
- installation directory contains custom MQL4 programs (Expert Advisors, indicators, scripts, etc.) not included in the standard delivery of the terminal's old version.
After the user data is copied successfully and the update is complete, users will see a dialog window containing the full paths of the source folder and new data folder:
Additionally, the terminal's Journal will contain messages about all the movements of the user data performed during the update.
Full info: https://forum.mql4.com/60555