NTREGOPT will minimize the size of the registry files and optimize registry access. The program works by recreating each registry hive "from scratch", thus removing any slack space that may be left from previously modified or deleted keys. The program does not change the contents of the registry in any way, nor does it defrag the registry files "on-disk" (as the PageDefrag program from SysInternals does).

Ссылка: http://www.derf..regopt-setup.exe