Security Update KB2686509 will not install- error code 0xf0f4

Wow you saved me from so much 'update' distress. Indeed I had done a similar thing somewhere in my distant memory. Simply deleting my hacked registry key entry as shown below solved my problem.

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Keyboard Layout]

"Scancode Map"=hex:00,00,00,00,00,00,00,00,02,00,00,2a,00,3a,00,00,00,00,00,00

I struggled with this for days. Here is what was happening and what I did that worked.

faultykeyboard.log listed 24 entries of the form   kb*.kbd

I searched and no such files exist on my computer.

By running regedit and looking I found 24 abnormal looking subkeys matching the list in:

HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Control/Keyboard Layouts

After carefully reviewing the potential for damage I discovered that the operating system automatically restores this section of the registery if a boot failure occurs.

I then boldly deleted all subkeys of the type *.kbd from the registry. I deleted faultykeyboard.log. I rebooted then ran the update KB2686509 and it installed and rebooted the computer.

The problem is gone.  Everything works.

Good tips in this thread. It ultimately led me to my solution. The problem computer here was also running a version of Windows XP modified with NLite.

I was able to resolve this problem by first opening the faulty keyboard log. On the problem computer, it was located in C:\Windows\system32\faultykeyboardlog.log.

The faultykeyboard.log file simply listed these four items:

KBDDV.DLL

KBDUSX.DLL

KBDUSL.DLL

KBDUSR.DLL

I went to a computer that I knew had an unmodified version of Windows XP Professional, copied those four DLL files from C:\Windows\system32. I then transfered them to the C:\Windows\system32 on the problem computer and re-ran the manual installation file for KB2686509 which can be downloaded at http://www.microsoft.com/en-us/download/details.aspx?id=29804.

Problem solved.