While it is good idea what you are thinking, most of the windows update updates are windows version specific.. There some that are generic to all ose. All of the updates will have a number associated with it IE 810565 for example. If you go to Microsoft's
Knowledge Base Search By Article ID and enter the number, some will have a download fix there.
2) A way that you can minimize the number of downloads required is get and install the latest Service Packs for your version of windows (2000 up tp SP3, XP up to SP1) and that will help cut down the number of updates on the WindowsUpdate Site
Dahak