Article ID: 2000608
After you install Internet Explorer 8, you may no longer be able to perform client-side script debugging using Visual Studio 2005. This issue is discussed in http://blogs.msdn.com/greggm/archive/2009/04/01/script-debugging-broken-in-vs-2005-after-installing-ie8.aspx.
Microsoft has confirmed that this is a problem in Visual Studio 2005.
In most scenarios, setting the registry value TabProcGrowth to a DWORD value of 0 is sufficient to resolve this problem.
However, if you are using Windows Vista, you will need to follow ALL of the steps below to resolve this issue:
This is a problem in Visual Studio 2005; the problem does not occur with Visual Studio 2008.
(http://go.microsoft.com/fwlink/?LinkId=151500)for other considerations.