I am getting the following problem when trying to install the module "No module called base."

First of all thank you for making it so easy to post a question here without asking me a million questions about my nationality , blah , blah.

My problem is:

When I try to install the powermail module it gives me the following error:

Environment Information :
System : Windows-XP-5.1.2600-SP3
OS Name : nt
Operating System Release : XP
Operating System Version : 5.1.2600
Operating System Architecture : 32bit
Operating System Locale : en_US.cp1252
Python Version : 2.5.2
OpenERP-Client Version : 5.0.6
Last revision No. & ID :Bazaar Package not Found !Traceback (most recent call last):
  File "netsvc.pyo", line 244, in dispatch
  File "netsvc.pyo", line 73, in __call__
  File "service\web_services.pyo", line 639, in execute
  File "service\web_services.pyo", line 619, in _execute
  File "wizard\__init__.pyo", line 178, in execute
  File "wizard\__init__.pyo", line 74, in execute_cr
  File "C:\Program Files\OpenERP Server\addons\base\module\wizard\wizard_module_upgrade.py", line 92, in _upgrade_module
  File "pooler.pyo", line 62, in restart_pool
  File "pooler.pyo", line 40, in get_db_and_pool
  File "addons\__init__.pyo", line 728, in load_modules
  File "addons\__init__.pyo", line 578, in load_module_graph
  File "addons\__init__.pyo", line 406, in register_class
  File "C:\Program Files\OpenERP Server\addons\poweremail.zip\poweremail\__init__.py", line 26, in <module>
  File "C:\Program Files\OpenERP Server\addons\poweremail.zip\poweremail\poweremail_core.py", line 32, in <module>
ImportError: No module named base