Update of MT4 to build 600/ New installation MT4 Client Terminal is on Build 600

TAKE NOTE: It is NOT a requirement to update MT4 to latest build 600. Some EAs may not support latest build. The EAs provider have to update their EAs to support it.

However, most of it have no issue.

Some clients terminal are forced to update MT4 to new version build 600.
However, new installation of MT4 are ALL on build 600.

In case you are unsure which version you are in, in the MT4 client terminal, go to "Help > About"


Look out for "Build 600" (image below is Build 509)


Most importantly to know is that the Experts, Indicators... folder have moved a little...

Read more below...

Automatic copying of MQL4 applications when updating from old builds

In the previous builds of MetaTrader 4 client terminal (509 and older), all MQL4 applications were stored in the following subdirectories of <terminal_installation_folder>\experts\ root directory:

• \experts - Expert Advisors (trading robots),
• \experts\indicators - custom indicators,
• \experts\scripts - scripts (MQL4 applications for a single run on the chart),
• \include - source code MQH and MQ4 files implemented into other programs,
• \libraries - libraries in the form of MQ4 source codes and EX4 executable files compiled from them. They are used for the dynamic call of the functions contained there by other MQL4 programs,
• \files - special "file sandbox". MQL4 applications are allowed to execute file operations only within this directory.

In the new MQL4 version, the file structure for storing the source codes has changed. Now, all MQL4 applications should be located in the appropriate folders of <terminal_installation_folder>\MQL4\ directory:

• \experts - Expert Advisors (trading robots),
• \Indicators - custom indicators,
• \Scripts - scripts (MQL4 applications for a single run on the chart),
• \include - source code MQH and MQ4 files implemented into other programs,
• \libraries - libraries in the form of MQ4 source codes and EX4 executable files compiled from them. They are used for the dynamic call of the functions contained there by other MQL4 programs,
• \Images - image files for using in resources,
• \files - special "file sandbox". MQL4 applications are allowed to execute file operations only within this directory.

When updating MetaTrader 4 terminal from build 509 to the newer version, all MQ4, MQH and EX4 files from standard root directories of the previous version are automatically copied and relocated to the appropriate folders.Subfolders additionally created by a user, as well as files contained there are not processed. They should be relocated to the new place manually if necessary.

No files or folders are deleted during the update! All file copy operations including used file paths are fixed in the terminal Journal during the update.

No automatic re-compilation of the old EX4 files to the new version is performed during the update. Users are free to decide what source codes should be compiled to the new EX4 version. All old EX4 will work in the new MetaTrader 4 terminal. EX4 libraries compiled by the new compiler can be called only from the EX4 programs that have also been compiled in the new version.

In some cases, you may need to edit the path in #property include for included files (if relative paths have changed) in the source files. Please note that MetaEditor's root directory is now <data_folder>\MQL4\. All programs should be located in the correct subdirectories. 

You can find the data folder (<data_folder>) for each copy of MetaTrader 4 terminal on your computer via the terminal menu or in MetaEditor: File - Open Data Folder.

source: http://forum.mql4.com/60075#filestructure

Additional Notes:
As a result of the recent MetaTrader 4 (MT4) Build 600 upgrade implemented by MetaQuotes, the folders within the MT4 folder have moved. In addition, the MQL4 language has changed, and this may have interfered with your installed Expert Advisors (EAs) and indicators.
As a result of this upgrade, you should firstly save your EAs and indicators in the new folder location,

Which is : MT4 > MQL4 > Experts/Indicators.

Secondly, you will need to align your EAs and indicators with the new language to ensure they are fully functional on the updated MT4 platform. To do this, there are two options:

Option 1 :
Contact your EA provider if you do not have the source code available and request an updated version of the EA.

Option 2 :
If you have written your own EAs or you do have the source code available,
please follow these steps:

‧ Navigate to Tools > MetaQuotes Language Editor – a new window will appear
‧ Navigate to View > Navigator – the Navigator box will appear in this window (if not shown already)
‧ Double-click on the EA/indicator you would like to use and update – the relevant EA script will appear in the main window
‧ Alternatively navigate to File > Open to locate the relevant EA/indicator source code saved on your computer
‧ Click on Compile in the toolbar on top of the main window (or navigate to File > Compile) – a message will appear in the
  Toolbox window at the bottom
‧ Once this has completed and there are no error messages displayed you will need to close and reopen MT4 your EAs
  and indicators should now be ready to use