尝试执行manage.py runserver时出现错误。 GEOS已经安装好了。创建数据库（我使用PostgreSQL），成功安装了所有需求包。当我运行python manage.py runserver时，我会收到此消息。
(virualenv) C:\Users\Alexander\Desktop\myproject>python manage.py runserver
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\core\management\__init__.py", line 338, in execute_from_command_line
utility.execute()
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\core\management\__init__.py", line 312, in execute
django.setup()
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\__init__.py", line 18, in setup
apps.populate(settings.INSTALLED_APPS)
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\apps\registry.py", line 108, in populate
app_config.import_models(all_models)
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\apps\config.py", line 198, in import_models
self.models_module = import_module(models_module_name)
File "C:\Python27\Lib\importlib\__init__.py", line 37, in import_module
__import__(name)
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\contrib\auth\models.py", line 41, in <module>
class Permission(models.Model):
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\db\models\base.py", line 139, in __new__
new_class.add_to_class('_meta', Options(meta, **kwargs))
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\db\models\base.py", line 324, in add_to_class
value.contribute_to_class(cls, name)
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\db\models\options.py", line 250, in contribute_to_class
self.db_table = truncate_name(self.db_table, connection.ops.max_name_length())
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\db\__init__.py", line 36, in __getattr__
return getattr(connections[DEFAULT_DB_ALIAS], item)
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\db\utils.py", line 240, in __getitem__
backend = load_backend(db['ENGINE'])
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\db\utils.py", line 111, in load_backend
return import_module('%s.base' % backend_name)
File "C:\Python27\Lib\importlib\__init__.py", line 37, in import_module
__import__(name)
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\contrib\gis\db\backends\postgis\base.py", line 8, in <module>
from .features import DatabaseFeatures
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\contrib\gis\db\backends\postgis\features.py", line 1, in <module>
from django.contrib.gis.db.backends.base.features import BaseSpatialFeatures
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\contrib\gis\db\backends\base\features.py", line 3, in <module>
from django.contrib.gis.db.models import aggregates
File "C:\Users\Alexander\Desktop\myproject\virualenv\lib\site-packages\django\contrib\gis\db\models\__init__.py", line 12, in <module>
"See also https://docs.djangoproject.com/en/%s/ref/contrib/gis/install/geolibs/" % get_docs_version())
django.core.exceptions.ImproperlyConfigured: GEOS is required and has not been detected. Are you sure it is installed? See also https://docs.djangoproject.com/en/1.8/ref/contrib/gis/install/geolibs/
任何想法如何解决？
UPD：pip freeze的结果：
(virualenv) C:\Users\Alexander\Desktop\myproject>pip freeze
amqp==1.4.9
anyjson==0.3.3
beautifulsoup4==4.1.3
billiard==3.3.0.23
bleach==1.4.1
boto==2.0
celery==3.1.23
chardet==2.3.0
Django==1.8.2
django-ajax-selects==1.3.6
django-appconf==1.0.2
django-celery==3.1.17
django-celery-email==1.1.4
django-contrib-comments==1.6.1
django-datatable-view==0.8.3
django-debug-toolbar==1.3.0
django-extensions==1.5.5
django-filter==0.10.0
django-formtools==1.0
django-grappelli==2.6.5
django-haystack==2.4.0
django-liststyle==0.2a0
django-multiselectfield==0.1.3
django-nocaptcha-recaptcha==0.0.18
django-postman==3.2.2
django-registration-redux==1.2
django-schedule==0.5b0
django-static-jquery==2.1.4
django-tagging==0.4
djangorestframework==3.1.2
docopt==0.4.0
ecdsa==0.13
elasticsearch==1.7.0
Fabric==1.10.1
filebrowser-safe==0.3.8
future==0.9.0
geopy==1.10.0
grappelli-safe==0.3.13
html5lib==0.99999
ipython==3.1.0
jsonfield==1.0.3
kombu==3.0.35
mailchimp==2.0.9
Mezzanine==4.1.0
mutagen==1.29
oauthlib==0.7.2
opbeat==3.0.2
paramiko==1.15.2
Pillow==2.8.1
psycopg2==2.6
pyactiveresource==2.1.1
pycrypto==2.6.1
pygeocoder==1.1.4
pysolr==3.3.2
python-dateutil==2.4.2
python-ptrace==0.8.1
pytz==2015.4
PyYAML==3.11
requests==2.7.0
requests-oauthlib==0.5.0
ShopifyAPI==2.1.3
six==1.9.0
sqlparse==0.1.15
tzlocal==1.0
urllib3==1.16
vobject==0.6.6
Werkzeug==0.10.4