After upgrading to Cognos 8.2 I had an issue with my Cognos service not starting. The solution was to open Cognos Configuration and to rename the Cognos service.
Cognos Configuration / Environment / select the Cognos 8 service / right-click and rename / Cognos service restart.
Some people may also have come across this issue when dealing with the Cognos error message CFG-ERR-0106.