Why is Visual Studio 2010 not able to find/open PDB files?

I am trying to use OpenCV in VS 2010. I am an amateur, and I am learning first steps from the OpenCV wiki. However, when trying to debug my project, I get the following errors:

'C:\Windows\SysWOW64\ntdll.dll', Cannot find or open the PDB file 'C:\Windows\SysWOW64\kernel32.dll', Cannot find or open the PDB file 'C:\Windows\SysWOW64\kernellbase.dll', Cannot find or open the PDB file

I have those files in the right directory, so why can't it open them? What should I do to fix the problem?

First change the following parameters:

Tools -> Options -> Debugging -> Symbols -> Server -> Yes

Then press Ctrl+F5 and you will see amazing things.

I'm pretty sure those are warnings, not errors. Your project should still run just fine.

However, since you should always try to fix compiler warnings, let's see what we can discover. I'm not at all familiar with OpenCV, and you don't link to the wiki tutorial that you're following. But it looks to me like the problem is that you're running a 64-bit version of Windows (as evidenced by the "SysWOW64" folder in the path to the DLL files), but the OpenCV stuff that you're trying is built for a 32-bit platform. So you might need to rebuild the project using CMake, as explained here.

More specifically, the files that are listed are Windows system files. PDB files contain debugging information that Visual Studio uses to allow you to step into and debug compiled code. You don't actually need the PDB files for system libraries to be able to debug your own code. But if you want, you can download the symbols for the system libraries as well. Go to the "Debug" menu, click on "Options and Settings", and scroll down the listbox on the right until you see "Enable source server support". Make sure that option is checked. Then, in the treeview to the left, click on "Symbols", and make sure that the "Microsoft Symbol Servers" option is selected. Click OK to dismiss the dialog, and then try rebuilding.