Hi,
Did your Visual Studio work fine before? If it worked, please try to install the latest service pack for it or repair it. If you installed any Add-in for it, you can try to disable it to eliminate the possibility that third party Add-ins are causing problems.
If this issue appeared after you installed Visual Studio, please make sure that you installed it completely and correctly.
You also can try to run devenv /setup from VS 2003 command prompt.
I hope this helps.
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