hey according it has something to do with internet explorer 9
more information from this thread i found when google your error code.
http://answers.microsoft.com/en-us/windows/forum/windows_7-windows_update/windows-update-failure-error-code-9c48-unable-to/f6b7723b-095e-e011-8dfc-68b599b31bf5
the suggestion from there is to uninstall internet explorer 9 and try the windows update agian.