Metaquotes has released a new version of Metatrader 4 (Build 600+) with some MASSIVE changes! These changes may negatively affect you in two ways: 1. Changes to the MQL4 code may result in EAs not being compatible with the new version of MT4. Some of the vital functions and variables have been changed that may result in your EA failing to work. 2. Changes to the entire folder structure (such as the location of the Experts folder) designed to make Metatrader 4 more compatible with the Windows UAC security feature may break some EAs that use DLL files or other external resources to function. From what I've seen, Metaquotes and many brokers have released the new builds without any forewarning about the potential consequences. EA vendors are scrambling to release updated versions of their EAs that work with the new MT4 builds. Some already have, while others have sent warnings to avoid updating MT4 until they can finish their update. How to Avoid the Automatic Metatrader 4 Update I just tested this method on my PC and I believe this is the best temporary update "block" available. As of Build 509, Metatrader 4 now stores downloaded updates in a separate folder. The next time Metatrader 4 is launched, it checks this folder for updates and then applies them. Step 1) Locate the MT4 update folder. It seems that on Windows 7, 8, and Server 2008 (and possibly all others), Metatrader 4 stores pending updates in this folder: C:\ProgramData\MetaQuotes\Webinstall\mt4clw Note that "ProgramData" is a hidden folder so you may not see it in the list of folders on your C: drive. You can access it by typing in the path in the Address Bar of explorer: C:\ProgramData then press Enter and you will see the subfolders. Note: if you don't see the "Webinstall" folder, try using the Search feature on the entire C: drive to find it. Step 2) Delete the entire "Webinstall" folder. This prevents MT4 from loading those updates the next time it is launched. In my personal test, I observed the following behavior after deleting the "Webinstall" folder: On the next launch of MT4, there was a notice in the Journal log: 10:07:26 LiveUpdate: new version 4.00 build 604 is available When I closed and re-opened MT4 again, I noticed that it downloaded all of the updates (the "mt4clw" folder was re-created and filled) and this message was in the Journal log: 10:08:30 LiveUpdate: new version 4.00 build 604 is available 10:09:30 LiveUpdate: finished