Error code 643 is what is referred to by Microsoft as a Generic error code. This means that there are multiple reasons that Error 643 is appearing on your system. As there are many different reasons that it could occur listed below will be the main reason why Error 643 happens as well as possible ways to resolve the issue.
The biggest reason that Error 643 occurs is due to an issue that is happening on Microsoft’s side when attempting to provide updates to their customers. This being the case when either providing patches , Service Pack updates, or various other files that they are trying to release to their licensed users. In many instances the problems are related to the automatic updates that are being sent out and there is some type of communication error either between the system and Microsoft, or the licensing system and the update system.
With either of the previously mentioned issues the result is Error 643; and it is not good as the updates are required on your system to keep the performance high, as well as to cover any and all possible security threats.
As the cause of the issue is related to a network issue on the Microsoft side there are not a lot of options to resolve the issue. The first thing that many users will do is to ensure that there are no issues with their systems prior to the download. Many times incorrect system settings, and problems within the registry, can cause issues when attempting to communicate with the Microsoft servers. If you think that the problem could be related to a corrupt or invalid registry entry the best thing to do is to try a registry cleaner to resolve the issue that is creating Error 643.
If the problem is with the automatic updates then there is a way to remove the automatic updates option regarding Microsoft published updates and manually initiate the updates. Often times it is the automatic updates settings that are responsible for creating the 643 Error messages.