As you know when the letter w placed at the end of a word, it is pronounced like 'oo' in the words book and could as seen on the chart below.It can be shown as /w/ or /ʊ/ too in dictionaries.
I am not sure but I think it still can be pronounced like 'oo' in the word book even though the letter w placed as the first letter of a word.For example : Watch like ooatch or ʊatch.What do you think?
But when it comes to the word window, can we say the first letter w is pronounced like 'oo' like ooindoo or ʊindoʊ
the first letter w is pronounced like /v/ in the word volcano as seen in the chart? /v/indoo or /v/indoʊ