I know this post is a little late but I wanted share this info with others who are looking to fix this problem.
I came across the same problem today on a Windows 2000 Pro machine. I got the Visual C++ error and then I got an Internet Explorer error when opening the Task Manager. I tried running Dial-A-Fix, reinstalling SP4, reinstalling IE6 SP1, & even trying a repair installation of Windows. None of these worked. I then tried HijackThis before Wiping & Reloading and it fixed it. I don't know exactly which BHO, toolbar, or other program was the culprit. I just unchecked everything I could live without and it worked like a champ. I don't know why I didn't run HijackThis first.
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