A similar problem was once resolved by doing the following.
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Start > Run > and in the box that comes up type
regsvr32 softpub.dll
Then click Ok
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Also (since MSN Explorer isn't working also) the problem may be with the .NET framework installation on your computer (don't worry if you don't understand what I mean, you just need to download and install something). Try and download and install the
.NET Framework SDK Version 1.1.