Problem with sound

Hi guys,..there recently i just bout a 2.5" HDD for my laptop,...and re-installed Windows onti,...my laptop is an Acer Aspire 7000 and i downloaded the drivers from the acer europe website,..but when i tried to install the sound driver,..i got this wierd error 'microsift bus should be running on system before running installation',so basically i googled the problem and said that i needed to downloaded a certain upgrade,..so i downloaded it and and then it said to me service pack is newer then the update,im running Windows XP Professional SP3,..and im wondering what can i do,...ive lookled for an update for SP3 and it simply doesnt exist to me knowledge at least,..ive also turn on automatic updates and tried to fix it that way,..but to no avail,i even went on the microsoft website and tried to download the updates from there but no avail,..

Any and all help would be appreciated