Environment for this issue: Exchg 2007 Win2008 SP1 & 2 Domain controllers Win2003 SP2

If your exchange installation was working and then suddenly stopped working with the error below.( Try this if your having an installation issue to, allthough this specific issue appeared after it was working fine for a few months).

(Some services won’t start ??)

Microsoft Exchange Active Directory Topology Service

Process MSEXCHANGEADTOPOLOGYSERVICE.EXE (PID=3268). Topology discovery failed, error 0x80040a02 (DSC_E_NO_SUITABLE_CDC). Look up the Lightweight Directory Access Protocol (LDAP) error code specified in the event description. To do this, use Microsoft Knowledge Base article 218185, "Microsoft LDAP Error Codes." Use the information in that article to learn more about the cause and resolution to this error. Use the Ping or PathPing command-line tools to test network connectivity to local domain controllers.

Goto Active directory on your domain Controller and add your exchange server as a 'Computer' on the 'Domain Admins Group'. Thanks to cchalmer on this aswell.

This worked fantastically for me with a reboot.

Also you can ref:

http://forums.microsoft.com/technet/showpost.aspx?postid=599509&siteid=17&sb=0&d=1&at=7&ft=11&tf=0&pageid=0

Please use this at your discretion as its not an official solution only a different suggestion to address your  problem and not ideal from a privacy point of view. I have other alternatives in this blog which may address your problem without going down this road.