If I download X12-30196.exe using a XP SP2 machine (with GB's of free disk
space) cleanup disk, remove all temp files, deleting keys from registry,
empty IE cache, stop all services apart from essentials, read all the KB's
etc I still cannot extract X12-30196.exe and get "The installation of this
package failed"

If I download X12-30196.exe using vista and copy to a XP SP2 machine file
extracts, I have tried this a few times and to verify I have downloaded
X12-30196.exe to vista and XP at same time and only works on XP via vista.

Problem seems to be XP corrupting download.