We also tested everything in advance - the really old machines that could not be patched were replaced and the ones that could be fixed were fixed (I think it was a BIOS upgrade that needed to be run). I was on leave during that December and my boss and the PFY spent the night playing games until he was reasonably sure that nothing untoward would happen and then left to party.
The more interesting thing about that time happened in late October. The company that I worked for had recently merged with another company and IT had only just finished merging their operations. We were in two seperate buildings (across the street from each other). Anyway, in October a directive was sent out by Head Office that each branch had to procure, rent or otherwise obtain the following prior to 1 December:
A power generator capable of running the office, in case there was as total meltdown and the power utility could not provide power. The most important requirement was that all PC's and the server room must be operational.
Portable loos in case the municipality had a total meltdown and there were no water to flush the toilets (there were much gnashing of teeth in the press that automated systems would not be able to run in the absence of the expected power failures, or should their computerised systems fall over).
Tanks to store water - primarily to run the loos.
The local directors then called me in to get my take on that and to give them some guidance, as they had discovered that, IF they could get a suitable generator, it would cost almost their year's profit (supply and demand - the forward-thinking people having long ago secured what they needed at reasonable cost). Ditto for loos and water tanks.
So I said, let's look at this logically: what good would keeping the servers and PC's running do, in case of total meltdown? There would be no telecommunications, as the telco's back-up systems could only run for a limited time in any case. Furthermore, there was no guarantee that the entities we needed to communicate with, would have the capability to do so. So all we would be doing is generating power at huge cost to create Word documents and spreadsheets and store it locally. We have been doing that manually for donkey's years (wide-spread PC's only came into use late in the 80's, so most people still knew how to do it - in fact, there were a fair number of die-hards who still ran manual systems next to the computerised system, as they did not fully trust the new-fangled way of doing things) and could easily revert. Once the expected chaos has subsided, we could then just scan or copy everything, or type the hand-written documents if push came to shove.
We also did not need power for lighting (it being summer down here) and air-conditioning is really just a luxury that we can dispense with if needed.
As far as loos and water was concerned, I told them that I am sure all the valves could still be manually operated, so I do not foresee any interruptions there. As far as water was concerned, if there were no pumps to pump water into the reservoirs, having tanks on the premises would be redundant in any case, since there would be no water to fill the tanks to start with.
The end result was that a nice letter was sent back to HO, stating basically that they have discussed the matter and, given the possible scenario's, have decided to do none of the suggested steps, for the reasons I gave and the crippling financial burden were they to try and implement it.
And everybody was reasonably relaxed about the whole thing afterwards. Yes, there were plans made on how to handle total melt-down, and procedures circulated on how things would need to be done if everything was to be done manually again, but people were happily continuing as always.
That said: there is nowadays a lot of smirking about the non-event that Y2K turned out to be ( I suspect mostly by people who were not there at the time, or who did not know what had been done in order to avert problems), but that was only (as said by many in the know) because a lot of hard work and testing had been put in by a lot of people beforehand to make it so.
In some ways I think that they (we) had been too successful and did it too well, so that the general feeling was that a lot of unnecessary hype had been created.