In specifying a specific library the lib prefix should be omitted. Try
gfortran -o main.exe test_lapack.f95 -LG:\Myproject\LAPACKtest -llapack - LG:\Myproject\LAPACKtest -blas
and
gfortran -o main.exe test_lapack.f95 -LG:\Myproject\LAPACKtest -lblas