In the registry, under HKEY_LOCAL_MACHINE\Software\PharosSystems, there are a number of subkeys. If you expand all these out you will find Log subkeys associated with a number of keys. Each of these Log subkeys has a value called TraceLog, which is set to 1 by default. Set each of these to 0 and there will be no more logging from Blueprint. This does not affect the operation of the Tracker in any way.