Unable to install SP1 on 2008 R2 -- [HRESULT = 0x800705b4 - ERROR_TIMEOUT]

1. Open registry by run regedit.exe. 

2. Navigate to 

    HKLM\System\CurrentControlSet\Services\TrustedInstaller
    right click it and export it for a backup. 

3. Set this registry value: BlockTimeIncrement to “2a30” (3 hours timeout) 

     It should be “384” right now. 

4. You may receive error when you set this value,
    Please right click the “TrustedInstaller” key and 
     set the permission to “Full Control” to users. 

5. After that, try to install SP1 again, this time should work.