You never use the Isah Database Patch Engine directly. The IsahDBPatcher.exe uses the Isah Database Patch Engine in the background. This means that if you are going to apply a database patch from the machine on which you installed the Isah Database Patch Engine, a mapping to the folder \IsahSetup_[RELEASENO]_Isah\[UPDATEPACKNO]_[VERSIONNO]\Database_Patch\Patch_[DATABASENO] has to be present. Run IsahDBPatcher.exe from this folder. Please refer to the Update Guide for more information on updating databases.