“A critical update is needed. To continue this installation, you need to install Windows Update Agent 5.8.02469 or later..”
Some people may have encountered this message during installation of Windows Live Messenger downloaded from websites other than that of MSN’s. Like what happened to me, I download my softwares from FileHippo and when i tried to install Windows Live Messenger, that message showed up.
Upon doing some Google search, i realized that this will really happen especially if your OS is not being updated with Windows Updates. Since i usually have my Windows Update turned off, then this scenario is expected.
So how can we upgrade to or install the latest version of Windows Live Messenger? I’ve listed two ways i found:
1. The quickest and easiest way is to download Windows Live Messenger from the MSN website (This is I did and it worked!hehehe ). The installer there already comes with the installation agent Windows is looking for.
2. Turn on Windows Automatic Updates and download everything needed up to the latest patch. That would include the installation agent already after which you can already install Windows Live Messenger using an installer from other sources.
3. This is a step that would allow you to download everything up to latest patch as a package without turning on Windows Automatic Updates.
a) Download http://update.microsoft.com/redist/wuredist.cab from microsoft site.
b) Open the cabinet file and you will find an xml manifest wuredist.xml. Open it using notepad or any text editor.
c) Check the DownloadUrl attribute for your OS architecture (x86, x64, ia64) for the download url from where you can get the download file. To know you OS architecture, right click on My Computer on your Desktop and choose Properties. In the General tab, under the Computer section, you’ll see it beside the Motherboard name. (e.g. AMD Athlon(tm) 64 X2 Dual Core Processor 4000+)
So for the x64 platform, the download url would be: http://download.windowsupdate.com/WindowsUpdate/redist/standalone/7.0.6000.381/WindowsUpdateAgent30-x64.exe
d) Download the file and install.
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wow that really worked thanx m8:)
i would like to install msn messanger but it says a critical up date is required that windows update agent 5.8.02469 or laters
thats exactly my scenario. its eaither you try download that update agent or download windows live messenger thru the msn website: http://im.live.com/Messenger/im/Join/
works great! thanks kath!
Great job, girl!
I’ve checked like 7 or 8 websites searching for the solution and I am certainly ending my search right here. I started reading this and rushed to the bottom to leave a reply before I had even read the whole article 
I just had to thank you for such a simple yet effective explanation.
yay! im glad i was able to help you guys. this steps did help me too when i experienced it before.
got it working on my wifes pc.
went to windows auto updatess and installed their latest installer. Then something about it trying to install windows genuine advantage which freaked me out so I cancelled it.
Apparently just installing the updater from their site is enougth as then I tried to insstall latest msn and went in like a dream
jobs a good un