first, did you install all drivers??
if not then I need the make,
model and model number of your pc,
laptop or desktop ??
You will have to go to a working pc and download, sp3 to a flash drive and then install manually as microsoft updates will not work without sp3.
when it is installed, there will be many updates so install only about 50 at a time.
if you have a hp, you might need a patch first before sp3, read below:
Courtesy of Tricky 300
Before you install SP3 read this article…
http://support.microsoft.com/kb/950717
…and if your PC is an HP Pavilion, Presario or Media Center and has an AMD processor you need to install this patch before installing SP3…
http://h10025.www1.hp.com/ewfrf/wc/softwareDownloadIndex?cc=uk&lc=en&dlc=en&softwareitem=pv-60484-2
…to find out if you have an AMD processor...
• Hold down the Windows key (between Ctrl and Alt) and hit the Pause Break key
• Your processor type is shown in the Computer: section
Then install SP3 by downloading and running from...
http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=24
…you can ignore the text that says that it is for network installations and also ignore the text advising Windows/Microsoft Update if only updating one PC.
Reboot twice after installing.
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also, you should download an offline install of your antivirus and install before you go to windows updates.
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also, what service pack are you on now??
32 or 64 bit??