Normally, when I see ～ことになる I translate it as "it is / has been decided that ～". However, in these few sentences the usage of ことになる is rather peculiar:
It's a snippet from BCCWJ, yahoo database. I am unsure if it's a dialogue or monologue (speaker contemplating the possibility of Windows being delayed) or what the exact function of ことになる is in the third sentence.
I translated the whole thing as:
"I'd like to buy a new computer along with new release of OS (Windows), but when? It seems it'll be released by the half of the next year, but there's a possibility it'll be delayed. I'll wait for about 2 years."