Note, in the first link, everything except W3C is listed as correct, which is even more baffling for me, because somewhere the wrong information is being received, and it happened everywhere in the shop at once, across platforms.
You've got it all wrong as to where the problem lies.
First, there are two ways being used to calculate your geolocation. One of them uses online providers who have databases mapping IP addresses to locations. This is what you're seeing in the "Provider X" columns, which you state are indeed showing your correct location.
W3C doesn't provide a geolocation service. Instead, what the results of this (admittedly badly named) column indicate are what YOUR COMPUTER reports its location as being, using the W3C Geolocation API. The first link you provided above describes this succinctly in the text immediately above the map, where it states "The W3C Geolocation service determins location by the browser providing GPS location (if available) and signal strengths of visible WiFi annoucements" [sic]. Thus, the web page is asking your browser to report where it is located, and your browser is responding that you're somewhere in Ireland.
The question for you then becomes: where is my browser getting this bad data from? On Mac OS X, browsers get this from the Core Location Framework. While Core Location Framework can conceivably use a number of different factors to determine your location, typically it uses the detectable WiFi beacons in your area, mapping their SSIDs and MAC addresses, and their relative strengths to triangulate your location. On Windows it uses the Sensor and Location Platform to do much the same thing.
I don't know much in the way of details of the databases Apple and Microsoft are using on the backend to map your triangulated location based on SSIDs/MACs of visible WiFi access points, however there are a few ways the system can go wrong:
- - The SSID/MAC of your access point matches that of another access point somewhere on the globe (and for some reason, all the other access points in your vicinity aren't in the database), or
- - You've moved the access point in question from one location to another, and the database hasn't been updated yet. This could occur if, for example, you buy a WiFi access point used off eBay (for example), or you've moved your physical location, you've bought a refurbished access point, or your corporate IT has issued you a previously used access point from another office.
The fact that all your systems had this problem at the same time indicate it's probably one of the above. You can try to fix the situation by changing the SSID of your access point. Depending on the size of your facility, this may be more or less difficult, however it should hopefully make the incorrect results from your OSs' location services either report the correct location, or simply that your location is unknown. You may also need to change the MAC address of your access point(s), but I'd save that as a last resort. Note than making these changes should fix the issue with your systems reporting themselves as being in Ireland, but it may not result in them reporting the correct location (they might report they don't know their location at all). That's okay -- for Apple devices at least, you can fix this by simply having someone with an iPhone with Location Service enabled in the vicinity (Apple's data is crowd sourced automatically through the use of GPS co-ordinates and relative WiFi access point signal strengths (I'm not sure how Microsoft collects the information for their database, so I can't help you there -- a Google search might provide some answers).