Why use WinDbg vs the Visual Studio (VS) debugger?

What are the major reasons for using WinDbg vs the Visual Studio debugger?

And is it commonly used as a complete replacement for the Visual Studio debugger, or more for when the need arises.

Solution 1:

If you are wondering why you should use windbg over Visual Studio, then you need to read Advanced Windows Debugging. Any time you need to debug a truly ugly problem windbg has better technology to do it with than Visual Studio. Windbg has a more powerful scripting language and allows you to write DLLs to automate difficult problems. It will install gflags.exe, which gives you better control over the heap for debugging memory overwrites.

You don't actually need to run the install, you can just copy the files over and be ready to go. Also it installs adsplus.vb, so you can take mini-dumps of running processes. It is also very easy to setup to perform remote debugging. There is nothing better than being able to debug a problem from your own desk instead of fighting the 15" monitor that flickers on a test PC.

For day to day code writing I use Visual Studio, but once you need to start debugging problems from other computers or find yourself in a very ugly situation, windbg is the only way to go. Spending some time learning windbg is a great investment. Also if you look at crash dumps there are two great resources, http://www.dumpanalysis.org/blog and http://blogs.msdn.com/ntdebugging/default.aspx that do all their debugging using windbg.

Solution 2:

Here are some further links to help with using WinDbg, most are .NET specific.

• John Robbins talks about using cmdtree to create a command window.
• Here is a quick WinDbg/SOS cheat sheet (webarchive).
• If broken it is, fix it you should has a bunch of WinDbg/Sos related articles, mainly around debugging ASP.NET.
• Here is an old overview of SOS from MSDN mag. It is about .NET 1.1 so its age is showing.

Solution 3:

You don't specify whether you're debugging native or managed code. It doesn't affect the answer, WinDbg is extremely useful for both, but many people believe that WinDbg is somehow less relevant when debugging .NET apps. Not so. As a bonus, you can learn a lot about how the .NET platform works by debugging your .NET app in WinDbg with the SOS extension. Run up (or attach to) your .NET app in WinDbg and type...

.loadby sos mscorwks

...to be sure that you load the right extension for the version of the CLR in use. Then type...

!help

... to see what commands are available in the SOS extension.

I've heard it joked that Microsoft only has one developer tool, and it's WinDbg. Everything you could possibly want for debugging is in there, or in an extension. Sure, a subset of those things are also available in VS with a friendlier UI... :-)