About the Error
This message appears when a security update for Microsoft .NET Framework version fails to upload – either through windows update or by a manual download effort. There is no problem with the user’s computer or software and no modifications to the computer are needed. The problem lies with the Microsoft server or with the internet connection which may not be functioning properly or which may have inadequate bandwidth slowing down the traffic.
Windows code 643 - Repair instruction
Unless you need the update urgently, the best thing is to wait for a day and try again – hopefully the server issues will have been resolved and the download will happen. However, if the problem is not resolved or you do not want to wait, do the following:
1. Reset your internet connection speed to a slow rate such as 9600 bps and try to download again. If this does not succeed and if other sites and downloads are functioning properly, the problem lies with Microsoft. In that case the best course of action will be:
2. Go to http://support.microsoft.com/kb/902992/en-us and download the Microsoft Knowledge Base (KB) article. This deasl with similar problems and follow the instruction given in the entry about updates not being installed. This will normally resolve the problem.
3. However, if the issues persist the problem could be with your Windows Update settings which may have become corrupted or changed in some manner. If the two actions given above have not helped the best thing to do is to reset the Widows Update components. Go to http://support.microsoft.com/kb/971058 and download the article “How do I reset Windows Update components.” Ensure that you understand the process fully and then, after setting a System Restore point, follow the instructions carefully.
TipFor more information, please see: How to fix Update error #643