IIS4 Security Patches install sequence (latest file date in parens):
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iprftp4i.exe (1999)
chkenc4i.exe (1/31/2000, Web Release Date - 03/20/2000)
escseq4i.exe (2/28/2000, Web Release Date - 04/11/2000)
crsscri.exe (10/18/2000, Web Release Date - 11/02/2000)
secsesi.exe (11/09/2000, Web Release Date - 11/20/2000) 
arbexei.exe (11/13/2000, Web Release Date - 11/20/2000)
q276575i.exe (11/22/2000, Sequence not important - Phone Book Service)
Q280322i.EXE (12/20/2000 - install after fpse2k_x86_ENGv12.exe)
frgvuli.exe (01/24/2001, Web Release Date - 01/29/2001)