prolem in extensions

i have problem in extensions like .txt .exe .scr .jpeg
i can`t see any extensions

for example if i make right click and new text document it became new text document not new text document.txt



any help please

thanks in advance

Control panel -> folder options -> 'view' tab

Then clear the box for 'hide extensions for known file types' then click OK

lol

i had a computer from 9 years and never see ths option

thx