Hello, I try to install isa sp2 on on my isa2k (with sp1 and post sp1 hotfixes) working on widows 2003. Here some info from ISA2000ServicePack2.log "... 172.217: DoInstallation: CustomizeCall failed : 0xff4e 174.150: The program cannot register the fltrsnk1.dll file. Select 'OK' to undo the changes that have been made, or select 'Cancel' to quit. If you select 'Cancel', your system will be left in a partially updated state and may not work correctly. ... " Maybe You have suggestions how to correct this. Best regards, Tomasz Skorupa