Hi, sorry for some reason I thought you were on a nvidia chipset..

If you try here:
Ă‚Â*Intel® Chipset Identification Utility This is the main Intel site and the link is for identifying your chipset, from there you can then find the correct drivers for your chipset.
Once again sorry about the link for the hotfix, I'd forgotten I was running some beta software called Silverlight (you'll probably get asked if you want to run it yourself if you go to MS sites) Anyway after a bit of searching I found the 64bit version for the hotfix :
Download details: Update for Windows Vista for x64-based Systems (KB936357)
As for un-installing your drivers before installing the new set... Don't worry, Vista comes with its own generic set of drivers which it will use if you take the other ones off. A word to the wise though... When your doing this process I would set your update utility to off. Otherwise as soon as you un-install the drivers it will automatically download the same again. (This may have been happening anyway and is perhaps why you were getting problems replacing them). This is the same for changing graphic drivers too.