My only immediate comment is not to be too XP-centric in your thinking. Under XP this disk churning would likely be sourced to search indexing of your hard drive.
If you note the shown results in both of Robear Dyer's links above, this is not even close to the truth.
Things you can do:
Right click each drive in My Computer, Properties, and decide what folders you do want indexed; and those you do not.
Remember that Vista is very happy to create a local workstation index of all of your network shares. This needs to be controlled by you.
Remember that Vista in a Network setting, Domain or Workgroup, is more than happy to make available "offline" any active shares you have. This needs to be controlled by you.
Memory management choices are important. Vista does not use physical RAM or Virtual Memory (the pagefile) anything like Windows XP. You can expect as a Vista trait more intensive use of the pagefile. There are benefits from using
ReadyBoost that cannot be achieved with additional physical RAM, or pagefile sizing.
<~PAB wuz here>