Notes about the UPDATE file extension:
Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries, unused processes and other unfavourable system settings to identify slowdown issues.
The UPDATE file type is primarily associated with 'ISAPI Loader' by EGGcentric. The isapi loader is an isapi application that loads and unloads another isapi application. The loader works by unloading the currently loaded isapi application and replacing it with a new isapi application. This involves a total of 3 files: *.run = the currently loaded isapi application, *.update = the new isapi application that will replace the old one, and *.backup = a copy of the old .run.