Hi Chris,
You did not mention the Web Server that you are using? If you are on Windows Server 2003 and WebServer is IIS6 then make a right click on Server name or Site name in the left panel of IIS, click on Properties > Home Directory > Configuration and you will find the *.cfc, *.cfm, *.cfml etc for CodlFusion along with the path of the ColdFusion's version connector.
If you are on IIS 7/7.5, then make a right click on Server name/Site name in the left panel of IIS and on the right panel (in the Feature settings) click on Handler mappings. Just double click on any CodlFusion handler like , *.cfm and you will get the executable like C:\ColdFusion10\config\wsconfig\1\isapi_redirect.dll (if it is a CF 10 connector)
Is it only CF administrator that you are not able to login? What happens if you try to open any .cfm?
HTH 
Thanks
VJ 