code 641 windows update encountered an unknown error

Hi,

1.      Were there any changes made to your computer before the issue occurred?

2.      What is the complete error message or error code that you get when the updates fail?

3.      What are the KB numbers of the updates that are failing?

4.      What exactly do you mean by “My registry had almost all of it disabled and I just fixed that”?

I would suggest you to follow the troubleshooting steps from the articles below and check if that fixes the issue on your computer.

Method 1:

Disable the security software temporarily.

Disable antivirus software

http://windows.microsoft.com/en-US/windows7/Disable-antivirus-software

Note: Antivirus software can help protect your computer against viruses and other security threats. In most cases, you should not disable your antivirus software. If you do have to temporarily disable it to install other software, you should re-enable it as soon as you're done. If you are connected to the Internet or a network during the time your antivirus software is disabled, your computer is vulnerable to attacks.

Method 2:

Put the computer in Clean Boot state to see if there is any software conflict as clean boot helps to eliminate software conflicts.

Note: After clean boot troubleshooting steps, follow Step 7 from the link to return the computer to Normal startup mode.

Method 3:

You can also install the updates (KB number) manually by downloading from Microsoft download center.

http://www.microsoft.com/downloads/en/default.aspx

Method 4:

Follow the steps from article to reset the windows update components.

How do I reset Windows Update components?

http://support.microsoft.com/kb/971058

For reference:

Unable to install updates in Windows Vista, Windows 7, Windows Server 2008 and Windows Server 2008 R2

http://support.microsoft.com/kb/2509997

I hope this information helps. Please get back to us if you have any more questions about this issue.

Thank you for responding. I got the Microsoft .NET Framework 4 installed. I found a simple answer in one of these forums, Start >>> Control Panel >>> System and Maintenance >>> Administrative Tools >>> Services >>>Give User Account
Control password or confirmation >>> Scroll Down till you see "Windows
Installer" >>> Right click >>> Properties >>> Under the General tab, make sure the startup type is "Automatic".
I changed it to automatic and it fixed that problem but now i'm trying to upgrade to Windows 7 and it says "Windows Vista Ultimate cannot be upgraded to Windows 7 Home Premium" and I have to do a custom install. I ran the system compatibility test and it said my system was compatible. I think there's still something in my 'services' that is disabled and needs to be automatic but I don't know what. There's a lot of stuff disabled in there. Where do I get a list of the things that are suppose to be automatic, automatic delayed, or maual?