This update has failed repeatedly. I've followed the KB Articles procedures to remove and re-install all versions of .NET [1.1 and 3.5 SP1] but it still fails. http://support.microsoft.com/kb/923100/ Error details below: Microsoft .NET Framework 1.1 SP1 Security Update for Windows Vista and Windows Server 2008 (KB979906) Installation date: ‎6/‎22/‎2010 6:07 PM Installation status: Failed Error details: Code 643 Update type: Important A security issue has been identified that could allow an attacker to tamper with digitally signed content without being detected, when this content is being consumed by an application that makes use of the Microsoft .NET Framework on a Windows-based system. You can help protect your computer by installing this update from Microsoft. After you install this item, you may have to restart your computer. More information: http://go.microsoft.com/fwlink/?LinkId=185333

not sure if it was the same patch, but we had an issue with one of the dot net patches too on a few pcs. the solution was to download the patch manually, extract it and install the contained install package, which worked unlike the complete patch. you could give it a try

Hi Paul, Please perform a clean boot and manually download the update and install it again. Let’s see whether it will work. Please follow the steps below to perform a clean boot. A clean boot helps eliminate software conflicts. 1. Click Start, type msconfig in the Start Search box, and then press ENTER. If you are prompted for an administrator password or for a confirmation, type the password, or click Continue. 2. On the General tab, click Selective Startup. 3. Under Selective Startup, click to clear the Load Startup Items check box. 4. Click the Services tab, click to select the Hide All Microsoft Services check box, and then click Disable All. 5. Click OK. 6. When you are prompted, click Restart. 7. After the computer starts, manually download and install the update from following website. http://www.microsoft.com/downloads/details.aspx?familyid=5e55ee58-f00a-4237-bddc-492b63a18b96&displaylang=en Please also disable the anti-virus software in case of any failures. After you have finished troubleshooting, follow these steps to reset the computer to start as usual: a. Click Start , type msconfig.exe in the Start Search box, and then press ENTER. If you are prompted for an administrator password or for confirmation, type your password, or click Continue. b. On the General tab, click the Normal Startup option, and then click OK. c. When you are prompted to restart the computer, click Restart. Regards, Karen JiPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. This posting is provided "AS IS" with no warranties, and confers no rights.

Hi Karen, I tried the steps that you outlined and I am still getting the error code 643. Any other suggestions? Thank you, Mike