MSE Client Update Package - V4 failed

I got an update notice for an MSE Client Package to update to MSE V4 (KB2691905).
The update failed on Win7-x64 leaving no AV installed.

I tried to download MSE and I get a "Page cannot be found" at
Microsoft Security Essentials - Free Antivirus for Windows

I did find this page can download MSE, but I'm not sure what it would download/install...
Anti-Malware, Virus, Spyware Protection | Microsoft Security Essentials

If anyone knows more about this, I'd appreciate any info.

I re-booted the PC in Win7-x86 for now, using Avast ...

Not sure if this post should also be in "Windows Updates and Activation" subforum.
I don't want to duplicate a post...

Thanks,
David

I got the update notice yesterday and used your first link. When I clicked the Free* download button it showed an upgrade dialog box and the upgrade went smoothly. It's possible that you may have remnants of the old version of MSE that are preventing the new version from installing. This Microsoft KB article may help.

How to manually uninstall Microsoft Security Essentials 2.0.1963 if you cannot uninstall it by using the Add or Remove Programs item

I'd use the Fix it button first and then try to reinstall MSE. Remove Avast first through Programs and Features and then run the official Avast uninstaller to remove any Avast remnants.

avast! Uninstall Utility | Download aswClear for avast! Removal

If the Fix it button doesn't let you reinstall MSE then I'd try the "Let me fix it myself" steps.

Thanks, I'll try uninstalling MSE from X64 from your link/instructions.

I don't want to un-install Avast (yet).
This is a multi-boot PC and Avast is installed in X86, so it shouldn't cause a problem for MSE in X64...

It's only my TEST machine, so i can always fall back to system image backups

Thanks again

Hope the KB article helps. Please let me know how it goes so I can expand my own KB.

Well, i have MSE v4 installed.
I downloaded mseinstall.exe from this link, and it installed V4 without any issue.
Anti-Malware, Virus, Spyware Protection | Microsoft Security Essentials

I still get a page not found trying to download MSE from this link
Microsoft Security Essentials - Free Antivirus for Windows

My original concern was the update failed, and the page could not be found for the MSE download...
I thought there might be an issue with V4.
Now, i think MS has a bad link on that one page...

Not sure why the Update failed - gives me an Unknown reason...

Going through the links/instructions everything uninstalled correctly during the update...
Even a manual regedit found no remnants for MSE V2...

The page worked for me.;

Figured out the download didn't work for me with my Firefox/Waterfox Noscript addon settings.
I had to all allow aspnetcdn.com...
I've learned this lesson before, and yet again

Thanks for help in pointing me in the right direction :)