Refer customers to this URL if exiting the install due to wrong OS:
www.agilent.com/find/drivers

E1420B:
http://www.home.agilent.com/agilent/editorial.jspx?cc=US&lc=eng&ckey=879004&id=879004
"VXIPlug&Play Driver Version A.02.03 for E1420B"

E1412A:
http://www.home.agilent.com/agilent/editorial.jspx?cc=US&lc=eng&ckey=879020&id=879020
"VXIPlug&Play Driver Version A.02.08 for E1412A"

MS-Help util:
MS Help: Click Download for the Windows6.1-KB917607-x64.msu file at:
http://www.microsoft.com/download/en/details.aspx?id=91&hash=YtRLPwrnHwMrQ7GS8gj1Fx572NaptgAajEU3%2bZH2sQ3u%2bGhnVUT2ZzNdETrEEWiTg8VawcE1URw1ZBmMWlLwEA%3d%3d