Actually I had a second thought on this, all the modules are loaded no matter what configure you have. This is because we might need to do a parse_agent_config for some of the modules because we need to be backwards-compatible. This means on unix it'll have an error trying to load any checks.d modules like this:

```python
2013-10-24 15:24:40,279 | ERROR | dd.collector | config(config.py:639) | Unable to import check module iis.py from checks.d
Traceback (most recent call last):
  File "/home/vagrant/workspace/dd-agent/config.py", line 635, in load_check_directory
    check_module = imp.load_source('checksd_%s' % check_name, check)
  File "/home/vagrant/workspace/dd-agent/checks.d/iis.py", line 4, in <module>
    import wmi
ImportError: No module named wmi
```

so I'm going to leave it as-is.