Question : exchange 2010 installation

Hi
i am trying to install exchange 2010 in to my w2k3 AD environment. when it does the pre req it failed with following error

Error:
The Exchange organization is not in native mode.
Recommended Action: http://go.microsoft.com/fwlink/?linkid=30939&l=en&v=ExBPA.4&id=63bbe074-5dae-41b4-b71b-80ffb0b1d42b

as fas as i know we never installed exchange previously after looking the los it foiund Atest exchange organisation unit in AD .
it looks like some one has tried to install previously or attributes got installed.

can you help to remove these AD atributes . i am bit scared to remove from AD using adsiedit.

help !!!

Answer : exchange 2010 installation

1. Replaces the 'querystring' in a URL with &page=([0-9])+

2. Creates a 'new' object of the class F1.

3. 'Unsets' or makes null a series of cookie values.