Vista SP2 and .NET Framework 3.5 ERROR: TRUST_E_NOSIGNATURE(800B0100)

I have a laptop running Windows Vista x86, and I can't install 2 updates: "Microsoft .NET framework 3.5 SP1 and .NET Framework 3.5 Family Update (KB951847) x86" and "Windows Vista Service Pack 2 (KB948465)." The error is always: TRUST_E_NOSIGNATURE(800B0100). I know it has something to do with wrong registry, and I've tried almost everything I've seen from the Microsoft Website and other people's suggestions, but nothing has worked. For example, I've tried:

• Running the Windows Update Readiness Tool - it installs "Hotfix for Windows" update, but it doesn't fix the problem.

• Running Microsoft FixIt - but everytime it runs it says it fixes the same problems successfully, so I don't think it changes anything.

• I've run Registry Cleaner on Norton 360 Premier many times, as well as scanned for viruses.

• Disabling Norton every time I try to install the updates.

• Renaming the "C:\Windows\SoftwareDistribution" folder.

among other things, but none have worked. All the other updates install well. The only options I know of now are:

• uninstalling Norton and trying again

• using Microsoft's Premier Support Services ($99)

• reinstalling Vista using a CD (don't know how)

These options would either take a lot of time and effort or be too costly. If anybody knows of a simpler, easier, free option, please tell me.

Here is the CheckSur.log from C:\Windows\logs\CBS\: (for @magicandre1981) Updated

=================================
Checking System Update Readiness.
Version 6.0.6001.22275
2013-08-14 13:12

Checking Deployment Packages

Checking Package Manifests and catalogs.

Checking package watchlist.

Checking component watchlist.

Checking packages.

(f) CBS MUM Missing 0x00000002  servicing\packages    \Package_for_KB972260~31bf3856ad364e35~x86~~6.0.1.1.mum       

Checking component store

Checking SMI Store
Summary:
Milliseconds: 3233229
 Found 2 errors
  CBS MUM Missing Total Count: 1

Now that I know which files are missing, could somebody help me with finding them? I've found the first file, but now I can't seem to find the second file from the Microsoft website.

If somebody has the files I am missing and could send me a link to it, that'll be great.

Thanks.

2 files from the update KB972260 are damaged. Try to remove the update from control panel. If this doesn't work, download the update and copy it to %Windir%\Temp\CheckSUR and run the Windows Update Readiness Tool again. if this also doesn't work, copy the 2 corrupted files from a 2nd PC:

Microsoft explained his here in detail:

http://technet.microsoft.com/en-us/library/ee619779%28WS.10%29.aspx