Python(x,y) interferes with earlier Numpy installation

[beliavsky at aol.com]

I am running Python 2.7.5 on Windows 7 and installed Numpy, which worked.
Then I installed Python(x,y) from a file Python(x,y)-2.7.5.2.exe, and now running
the script

from numpy import array, size, shape, min, max, sum
a = array([1, 2, 3])
print shape(a)

gives the error messages

Traceback (most recent call last):
  File "x.py", line 1, in <module>
    from numpy import array, size, shape, min, max, sum
  File "c:\python27\lib\site-packages\numpy\__init__.py", line 153, in <module>
    from . import add_newdocs
  File "c:\python27\lib\site-packages\numpy\add_newdocs.py", line 13, in <module>
    from numpy.lib import add_newdoc
  File "c:\python27\lib\site-packages\numpy\lib\__init__.py", line 18, in <module>
    from .polynomial import *
  File "c:\python27\lib\site-packages\numpy\lib\polynomial.py", line 19, in <module>
    from numpy.linalg import eigvals, lstsq, inv
  File "c:\python27\lib\site-packages\numpy\linalg\__init__.py", line 50, in <module>
    from .linalg import *
  File "c:\python27\lib\site-packages\numpy\linalg\linalg.py", line 29, in <module>
    from numpy.linalg import lapack_lite, _umath_linalg
ImportError: DLL load failed: The specified path is invalid.

How can I get Numpy working again? Thanks.