windows7 64bitでSP1を入れようとしたら 0x800f0a12　エラー

You might encounter an issue during the installation of SP1 for Win7/R2 where the installer exits with: 0x800f0a12

This is due to the automount policy for your machine being set to disable. We block the service pack installation in these cases because we need to be able to write information to the BCD store during install and with automount turned off, we are not able to. To resolve this, re-enable automount and then install the service pack. Quick steps to do this in case you forgot are:

1. Run DISKPART

2. automount enable

3. Restart

4. Install SP1