Mac OS 7.5.4 or System 7.5.4 was a version of the Mac OS which reached Golden Master status and was slated to ship as an unified upgrade. However, just hours before it was slated to be seeded, distribution was halted. Mac OS 7.5.4 was released by Apple Inc. to a limited distribution, prior to an anticipated general release. Shortly after this limited distribution, it was discovered that some components had not been included in the installer.. Minor revisions between Mac OS versions 7.5.4 and 7.5.5 are: