There is a great tool coming with Visual C++ 6.0, it is called
"Dependency Walker for Win32 (Intel x86)". After right clicking your
application, just select "View Dependencies..." from the pop-up menu
and this cool tool will show you all the modules and dlls that your
selected application depends on. Consequently, if your selected
application had "mscoree.dll" as one of its modules, it is Dot Net,
other wise, it is not.
(You must have VC++6.0 installed to use that tool)
Hope this help