VC6 was designed at the times of Windows 9x and NT4 and has been updated to run with Windows 2000 and XP. Even Visual Studio 2003 does not run without problems with Windows 7.
The best solution is to use a Windows versions that is supported by VC6 (e.g. using a virtual machine; if your Windows is a Professional version you can use the XP mode).
Otherwise search the net for tips on how to setup VC6 with Windows 7:
How to install Visual Studio 6 on Windows 7 professional 64bit[
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