Data Execution Prevention (DEP) is a security feature that is intended to prevent an application or service from executing code from a non-executable memory region. Software implementation of DEP in Windows operating system is also called Safe Structured Exception Handling (SafeSEH) by Microsoft. DEP may cause application incompatibility problems, especially when a non-DEP compliant extension is added, as DEP is applied to an entire process.

To fix problem arising from DEP protection when executing a software program, user can turn off and disable DEP globally, turn off or disable DEP entirely for all non-essential Windows programs and services (default for Windows XP and Windows Vista), or DEP can also be turned off or disabled on a per-application basis.

Microsoft Office application suites and programs are subjected to DEP protection too. User who facing problem when using Office applications can use the following trick to turn off and disable DEP for Office applications.

How to Disable DEP for Microsoft Office

To disable DEP for Office programs automatically, download and run the following Microsoft Fix it 50284 wizard: MicrosoftFixit50284.msi

How to Enable DEP for Microsoft Office

To enable DEP for Office programs automatically, download and run the following Microsoft Fix it 50283 wizard: MicrosoftFixit50283.msi

Source: KB971766