I have several machines in one building in our company that have issues that seem to come and go. The symptoms are all the same. The machines boot slowly, and then after fully booting, some apps will run, some won't. Sometimes none will, but usually, like Outlook will open, but then Excel will not...
I've tried narrowing the problem down... I can move the machines to another building and the issue always goes away. I have checked the power in the building(had maintenance do it), and even went so far as to put a known good UPS that was server quality on an offending machine with no results. Doesn't matter if I unplug the network cable from the machine or leave it in, so it's not a network issue...
When it happens you can tell immediately, because Symantec Endpoint Protection will not fully load. If Endpoint loads then I know the machine will run perfectly. But, having said that, it can't be an Endpoint issue because it goes away when I move the machine to a different location.
What can it be about that location? It only happens to machines in that building, and intermittantly... :(
I've come across this problem before and the problem was that someone had plugged in a network cable for a completely different network into the switchbox so every computer was trying to grab information from 2 different networks and it was confusing itself. I see though that you've tried it while the computers have no network cable connected so that couldn't be the problem.
By the sounds of it, there's some sort of interference if it's happening to the machines whether they're connected to a network or not. Is there something in the problem building that isn't in the others?
Ah... but it happened even with the network disconnected from a computer. I'm looking at a common culprit, and you happened to drop the name of a good start. Symantec Endpoint. How often did you try a particular machine in a different location? Could it be RFI? Do these machines have wireless networking cards fitted? Because then it could be wireless hacking [of your network or individual machines]. If you find a good location does it always stay good? Simple, reorganise your office.. :)
The only real issue with the building is, that we are a forge and machine shop, and this particular building is the closeset to the forge. You can feel the vibration from the forge hammers quite well. The only problem I have with blaming it on the forge is that this building has been there, and the forge has been there since 1941. And, while we haven't had computers in that building since 1941, there have been pc's in that building since 1990 at least, and the problem is a fairly new one that affects both older machines and new ones, but only intermittantly... I may have to check to see if the forge has added a bigger hammer than ever used in that location before and that I'm unaware of. I suppose it could be that the hammer is hitting and shaking the building at just the right moment during boot to cause some problems. Since I first posted this, I had a new user in that building get a brand new pc... I loaded the machine at my office in another building and carried it out to the user and the machine did the usual half boot sort of thing, where Endpoint didn't load and some applications would run and others not. I told the user to just leave the machine running since it was end of day, and let's see where the machine was in the morning... after leaving the machine running all night the next day it was fine.
There is no wireless in this building, and unfortunately no other place to put the 10 or so endusers in this building...
Electric arc furnaces? I always feel uncomfortable about hdds and vibration/shock, esp while they are reading/writing [the heads sit on the disk surface at no/low speeds, and ride on a molecular dimension air cushion at normal speeds]. But makers say they can take 5 or more G's, so.... Anyway, to eliminate vibration try a foam pad under a sys. Anyone with a fluffy beard should be wearing some sorta stocking over it in a machine shop. Simply safety.