The only thing I can think to do is to boot to the Repair Environment, and rename the file there.
Reboot the computer, and tap the F8 key until you get the advanced boot menu up - one option should be 'Repair your computer'. Pick that one.
Log into your normal account.
You'll get a set of options - pick the Command Prompt one.
At the command prompt, type DIR C:\
- if we're lucky this will bring up a listing of your normal C: drive contents, including the Program Files folder(s) and the Windows folder.
If not, try D:\ or E:\ (etc. until you get the right letter)
then type the following command
REN <drive>:\Windows\winsxs\pending.xml pending.old1
see if that works - if it does, then try running the SFC from there...
sfc /scannow /OFFBOOTDIR=<drive>:\ /OFFWINDIR=<drive>:\Windows
where <drive> is the letter you found above.
Wait for the command to complete. (make a note of the response!).
Once it has, type EXIT and the pick the option to reboot.
Boot to Normal mode, and run another SFC /SCANNOW - this will update the CBS.log file (the one in RE couldn't)
Please attach teh new CBS.log file to your response.