Are you trying to download a specific Acrobat update? If so which one? Could you also please provide the error message? Also what version of Windows are you using?
to close adobe 8 whihc is not open
It is. Task Manager --> Processes tab --> acrotray.exe. Terminate the process.
is there an update in my existing adobe 8? If so how do i start it?
You're two versions out of date. You did get that warning and upgrade requirement for a reason in teh first place....