i had an old iLok installation and after windows update it's all stopped to work.
it was a v3.1.7.1901 of 2017 well first you can disable loading driver tpkd.sys in registry or move it from system32/drivers
in windows/installer folderi had 3d21e.msi 451f672.msi, but you can just check the date of installation of PACE
(if you can, because windows will erase it, so check the iLok folder date)
you can try to uninstall with right click on .msi file, but it didn't anything for me and i had errors with install
so then i opened regedit (try O&O regedit - it's free) and search for words "iLok" and "PACE"
you will find some - right click in the left part and export full "folder" of that string, then clear or delete it, go for next
when you clean all (i had 3-4), you will be able to install new v5 or whatever it will be.
if you will have old installation - you can get an error after rebooting tpkd.sys incompatible blue screen
boot from any windows installation media, goto cmd
open regedit and load hive /system32/config/SYSTEM get to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tpkd
set start=4
or you can get autoruns by sysinternals and boot windows from some windows.live.boot DVD, or previous version backup,
i had an old version, so i booted into it or just get hd to another comp, then run autoruns with admin rights and you'll get "load Offline"so when youload it, go to drivers and find tpkd.sys to disable. go back to normal boot.
you can revert many boot errors this way.