There are oh so many NEW hiding places (THANK YOU Microsoft for all of those four year old resurrected security holes PLUS new places to hide them in) which needed to be added to HARD BOClean code (rather than previous "well, let's have a peek") but in general, BOClean *should* be running faster than before owing to the consolidation of all those "various" ... my suspicion is that as before, we've got some bad rootkitting slowing things down and the only reason that it might not have been noted before is that we're peeking and poking in places that are confusing someone else. I offer the "Process Guard/NOD32" reality in "BOClean is killing my CPU time with spikes" silliness. But yeah, startup does a WHOLE raft more things than it did in earlier versions, trying to snapshot "virgin" views of the system in case ANYTHING anywhere changes. Didn't have to do as MUCH of it as we used to. But there's an ADVANTAGE to this startup phenom. We're doing a papparazzi on everything. And that means that it won't have to be done again once you're GOING ... so long as things don't CHANGE ... The MAJOR effort in 4.20 was to get that CPU time down, as well as what had to be REchecked in order to reduce the "spikes" ... "up front" was the cost of the solution, SO much more info to gather ... up front.