Cannot install "Security Update for Microsoft .NET Framework 3.5.1"

Hi,

I have an update which refuses to install:

Security Update for Microsoft .NET Framework 3.5.1 on Windows 7 and Windows Server 2008 R2 SP1 for x64-based Systems (KB2742599)
Download size: 8.0 MB
You may need to restart your computer for this update to take effect.
Update type: Important
A security issue has been identified that could allow an unauthenticated remote attacker to compromise your system and gain control over it. You can help protect your system by installing this update from Microsoft. After you install this update, you may have to restart your system.
More information:
MS13-004: Description of the security update for the .NET Framework 3.5.1 on Windows 7 Service Pack 1 and Windows Server 2008 R2 Service Pack 1: January 8, 2013


The installation keeps failing due to uknown error with a code: 800B0100

1. System Update Readiness Tool - every run it succesfully installs one update, but nothing changes, Security Update for Microsoft .NET Framework stays uninstalled.

2. SFC Scan - Windows Resource Protection did not find any integrity violations

3. Error Code - 800B0100

4. Logs - I couldn't attach the whole CBS file, because
"500 - Internal server error. There is a problem with the resource you are looking for, and it cannot be displayed."
However I uploaded CBS file on sendspace: Download CBS.zip from Sendspace.com - send big files the easy way
If the CheckSUR.log file is the only one needed, you can find it attached below

5. Additional info - I'm surprised such error occured. I installed Windows 7 on formatted disk a week ago.

I hope I wrote everything needed in order to makes things easier for You. Any help appreciated :)

Thanks,
Pete

I downloaded and installed this update manually and it helped... So solved I guess.