Fixing the Visual Studio 2010 and IE10 web application debugger attach problem with RegSvr32

If you are using Visual Studio 2010 and you have updated your browser to Internet Explorer 10, you might have seen an error message when you try to start debugging (running) your web application:

Attaching the Script debugger to process '[1234] iexplore.exe' on machine
'DEV-1' failed. A debugger is already attached.

I've seen this error message on my Windows 7 development machine after updating to IE10. There are also other posts on this same topic, but luckily, the solution is simple: you need to re-register Visual Studio's debugger module with a single command-line command:

regsvr32 "C:\Program Files (x86)\Common Files\Microsoft Shared\VS7Debug\msdbg2.dll"

This command work on 64-bit machines, remove the " (x86)" part from the path if you have a 32-bit system. After you run this command as an administrator, the problem goes away. Remember to close both IE and Visual Studio 2010 before running the command.