This is the 1727th most frequent Russian word.
высокого
"Высокого" in English means "high" or "tall" (genitive/accusative singular masculine form, or genitive plural).
In this sentence, "высокого" is used to describe the quality of the windows, implying that they are of high standard.
Этот дом имеет окна высокого качества.
This house has windows of high quality.
Here, "высокого" modifies "результата," indicating an impressive or exceptional level of achievement.
Он добился высокого результата в соревновании.
He achieved a high result in the competition.
In this context, "высокого" relates to the physical height of the hill.