for the 2nd time, i am having problems with windows updates. i am receiving windows update error 80070490. this pc was given to me for free and it has windows 6.0. I do not want to invest the $ for windows 7 on this pc. is there a safe way i can fix this error given the above info. I have a windows vista home premium 64 bit system with service pack 2. everything including my security settings seem to be going haywire since i've tried to install the updates. i am an avid pc user and am learning my way around this pc which i really love

i appreciate the prompt replies to my request. however, since this pc was given to me i do no have any windows dvd to put in. it cost me $70 for norton to take over my computer and fix a windows update problem a few months ago.
it was a different error code (80071AA7) it is my understanding that internet explorer 9 came through as a windows update. I had them uninstall windows 9 because it was causing all these problems and i think (?) what they did was exactly that and now i have internet explorer 8. everything was working fine until this recent update request. also, google is requesting an update request and when i click continue-it does not seem to take because everytime i turn my pc back on-it still requests the google update (along with the red shield for the windows update). i have been cancelling the google update request since then every time it shows up. am i doing something wrong?