Here is a handy Script by fxsaber that can be used to stop MT5 from prompting you to update.
It can prevent MT5 from updating to the experimental Beta versions because it blocks all updates.
The Script includes fxsaber's MTTester file and requires DLL access, so be sure to check off Allow DLL imports upon attaching it to your chart. If you are not comfortable with enabling DLL's or not familiar with fxsaber's work, then simply don't use the Script. After enabling DLL's, you will see the OK button and click it.
To turn updates back on, just reattach the Script to your chart and it will ask you if you want to switch from OFF to ON--or ON to OFF depending on your last setting.
Both the Script and the include file are attached below in this Blog post. The LiveUpdate_On_Off.mq5 file should be saved to your MQL5==>Scripts folder, and the MTTester.mqh file must be saved to your MQL5==>Includes folder.
