win7Pro 32 bit KB2971850 (only) update Error 800B0100 (son's laptop)

Not a problem - only one file found now...

Code:

17968: 2014-10-12 08:30:31, Info                  CSI    000001dd [SR] Repairing 3 components
 Line 17969: 2014-10-12 08:30:31, Info                  CSI    000001de [SR] Beginning Verify and Repair transaction
 Line 17974: 2014-10-12 08:30:41, Info                  CSI    000001e1 [SR] Could not reproject corrupted file [ml:520{260},l:46{23}]"\??\C:\Windows\System32"\[l:30{15}]"NlsData004e.dll"; source file in store is also corrupted
 Line 17983: 2014-10-12 08:30:45, Info                  CSI    000001e3 [SR] Repair complete

Sometimes we get a domino effect like this - but sometimes this is caused by bad hardware, such as RAM or HD, and sometimes by malware.
This doesn't look like malware or an HD problem to me - so perhaps a RAM test is in order....
RAM - Test with Memtest86+
Run at least 3 full passes - although some recommend 8, I don't really believe assertions that this is necessary in every case.

I don't think there's anything to be gained by leaving it longer.

I have to go out now - I'll post a fix when I get back (if I'm in a fit state! )

Very good

Definitely stop it now - it's not going to catch anything it hasn't already found.

I'll post a fix for the file problems when I can see straight

I've uploaded a file - wgbad.zip - to my OneDrive at Noel's OneDrive
Please download and save it.

Right-click on the saved file and select Extract all...
Change the target to C:\ and click on Extract
Close all windows (it would be a good idea to print these instructions!)

Now reboot to the Repair Environment - as soon as the machine restarts, start tapping F8 - this should bring up the Advanced Boot Menu, at the top of which should be the option 'Repair my Computer'
Pick that
You'll have to log in with your username and password.

Pick the option to use a Command Prompt
At the prompt type
DIR C:\wgbad
hit the enter key - if you get a 'Not Found' error try
DIR D:\wgbad
or
DIR E:\wgbad



The drive letter in use when you find the folder will need to be substituted (for<drive>) into the following command...



XCOPY <drive>:\wgbad <drive>:\windows\winsxs /y /i /s /v /h



(e.g. XCOPY P:\wfire P:\windows\winsxs /y /i /s /v /h )



run the command (it should take almost no time) and when the prompt returns, type
EXIT
and hit the Enter key to exit Command Prompt - reboot to Normal Mode Windows.

Now run SFC /SCANNOW in an Elevated Command Prompt
then reboot and upload the new CBS.log file to your reply

Please post the new logs - they should tell us exactly what's wrong.