How to type accented letters
I know there has been a lot of confusion over this, I hope this helps. If you have Windows 10 you can easily change your keyboard setting. At the bottom right hand side of the screen you should notice a message box that says ENG next to it. You can change it to Irish (GLE). To input an accented letter just hit CTRL + ALT + letter of choice. If you have a previous version of Windows you should go into settings/time and language/ then you can change the keyboard.
It does change other keys too. for example, if you hit SHIFT + " it will type @. It might be annoying but it beats trying to type a code or having to search for a symbol. I hope this was helpful.
If you're American, and don't wish to change to the entire Irish keyboard layout, you can also use the US-international keyboard. It keeps the US layout, but includes the accent marks with the ALT-GR button + letter.
A big benefit of using the US International layout is that it's more versatile, so for most European languages you can stick to one layout, which is a big plus for me.
Of course, the Romanians decided they needed a breve and a comma below, which nobody else uses, so US International won't help you there. (Why they couldn't have gone with, say, a grave and a cedilla is beyond me. I know the breve was derived from Cyrillic, which is odd given the motivation for the spelling reform.)
US-International also does this weird thing with the single-quote and double-quote characters. You can put a fada on a vowel by typing a single-quote and then the vowel. But if you use double-quotes much, US-International can get a bit frustrating.
Eh, you get used to it. All it does, really, is open up even more accented letters (in the case of the double quotes, umlauts) and still works normally on most letters. I found that easier than switching to an entire new keyboard layout.
They're both good options. I just found that, once I discovered the WinKey+Space hotkey for switching between keyboard layouts, the GLE keyboard was better option for me.
And for balance, I should also add that GLE messes with double-quotes too, if you're used to a US keyboard, by moving it to a different location on the keyboard.
When The Irish Keyboard (GLE) is selected, you can just use the right hand Alt-key (ALT-GR) to get a fada on your vowels, which might be a little bit handier than CTRL-ALT-vowel, once you get used to it.
If you have multiple keyboards loaded, you can cycle between them by pressing the Windows key and the space bar, rather than using the mouse to click in the system tray.
Also note that if you have the GLE keyboard selected, tools like Windows Mail spell-check against an Irish dictionary so if you're typing your e-mails in English ,almost everything will be underlined, and words like "on" will be auto-corrected to ón.