What Is JIT Debugger?

Just-In-Time Debugger, a debugging tool included in Microsoft Visual Studio, launches the Visual Studio Debugger automatically when an outside program encounters a fatal error. The debugging tool's called "Just-In-Time" because it allows you to examine the fatal error before the operating system terminates the program.

JIT Debugger helps write computer programs.

Microsoft Visual Studio

Microsoft Visual Studio, as an Integrated Development Environment, can create applications, websites and web services for Windows-supported platforms. It's used most by those interested in programming, whether professionally or as a hobby. You can use the Visual Studio Debugger to debug applications written in any language supported by Visual Studio.


The debugging process reduces or eliminates persistent errors, or "bugs," in computer software or hardware devices. Coders write computer programs in different coding languages, which vary in their level of complication. Errors in coding results in a program acting differently than intended. A debugger computer program monitors a target program and identifies coding errors when it encounters a problem, allowing programmers to locate and address errors in a target program’s code. Debugging tools improve the stability of new software and hardware programs.

Enabling and Disabling

You cannot fully remove JIT Debugger, but you can enable or disable JIT Debugger by logging in to your operating system as an administrator and opening the Visual Studio application. Under the “Tools” menu, you select “Options,” followed by “Debugging” and “Just-in-Time.” To enable or disable JIT Debugger for managed, native or script functions, you need to check or uncheck the appropriate boxes. Only an administrator can enable or disable JIT Debugger, due to the crucial functions it undertakes in relation to target programs.


If enabled, JIT Debugger will launch the Visual Studio debugger even if Visual Studio isn't running. When an error occurs in the coding of a program, the operating system will not immediately abort the program. Instead, the program will remain active and a dialog box will open, prompting you to debug the program in question. For a program run by a different user, a security warning dialog box will ask for that user’s log-in details to proceed with debugging, to ensure that crucial changes to a program's code are only made by the user utilizing this particular program.


JIT Debugger comes free with all versions of Microsoft Visual Studio 2010 except for Visual Studio 2010 Express. The cheapest version that includes JIT Debugger, Visual Studio 2010 Professional, retails for around $549 on Microsoft.com as of June 2010.