Contrary to popular belief that everything will die and airplanes will fall out of the sky the second it turns to the year 2000, there will be problems before that,
and some have already happened.
For example, there was some trouble with a credit card company, because the expiry date on some cards read 1/01/00.
Also things like drivers licenses and bank machines, some of that is fixed but not all.
It's hard to say for sure, but the impact will be different in every country, for example, most of Russia's systems are not Y2K compliant, neither is Africa. While
Canada is one of the highest ranked countries for Y2K compliancy and so is the U.K. and U.S..
But many of the power plants are still not Y2K compliant.
Even if the government of the U.S. employed every U.S. computer programmer, they still would not have all the governments systems fixed in time for Y2K.
That is pretty much the same for every country.