Hi Necuima,
The way you call LoadLibrary looks reasonable and certainly works in Visual C++ (2010 Express).
Provided it's LoadLibrary that fails, one possible cause might be that the DLL and your executable don’t match in terms of being 32-bit or 64-bit.
A quick way to check that would be to add a line like this in your code:
int numBytes = sizeof( void* );
then check if the value of numBytes is the same in Visual C++ project and in your Dev-C++ project. Maybe your Dev-C++ project luckily matches the DLL, but the Visual C++ one doesn’t.
Another possibility is that one has been built with unicode support and the other one - without. You can check that in the project settings.
If you have the code for it, your best bet would be to rebuild the DLL in Visual C++ and make sure its settings match your app project settings.
Also, the error message you get looks like a red herring. Try adding GetLastError right after you call LoadLibrary and see if that gives you more useful information.
Good luck,
Radoslava, easynativeextensions.com