Windows Update always fails with the error code 770.
Manual installation attempts of the security updates also fail and the common cause is unsuccessful registering of the module FM20.DLL. Manual registering of FM20.DLL fails with the message: "The module FM20.DLL was loaded but the call toDllRegisterServer failed with error code 0x8002801c."
Most if not all hints on the internet refer to Windows XP and don´t apply to Windows 7.
This error has ocurred on two identical tablet PC:s, Fujitsu Siemens LifeBook T5010.
The closed title "FM20.dll Office 2003 on Windows 7" did not work.