I've only just started researching about this issue a couple of minutes ago, but thought I'd mention that I have two machines here right next to each other, both have hamachi set to auto update so the only hamachi installs/updates done on these systems has been by the program itself and in my case must have happened within the last few days as I was using hamachi to connect some sega emulators with a friend of mine last weekend.
Haven't checked with him yet to see if he's having the same problem, but for reference all of us are using windows 7 x64 pro sp1 with all recommended updates.
Not sure exactly when this issue started as I only really use hamachi on weekends and only noticed it last night sort of by accident while I was in the middle of troubleshooting a new game on my wife's system.
Anyway, just wanted to chime in with the information that this error can occur on systems where it wasn't a user initiated install/reinstall etc.
I have not done any troubleshooting steps as of yet, because in this situation the most obvious conclusion I can draw is that hamachi must have tried to update itself within the last couple of days and messed up it's own install using it's own installer. If that's the case it seems most likely to be some sort of bug with the installer, and trying to fix a bugged installer to fix it's own bugged installation seems somewhat counterintuitive.
Gotta go for now but the last thing I'll throw in is that the last thing I recall about hamachi before noticing this issue was after my play session with my buddy last weekend and just before he went offline, he reminded me that we were going to need to reset our clocks for daylight savings time.
First thing I noticed after seeing no connection between my wife's system and mine was that when I ran the diagnostic tool, it told me that hamachi needed to be reinstalled because of some sort of timestamp error.
Might sound silly, but is this just something caused/triggered by the daylight savings time change?