On two occasions when I had my computer’s hard drive replaced, and reinstalled MS Word, I found that Word documents was rendering all quotation marks as straight quotation marks rather than as curved quotation marks.
Here is how to fix the problem in MS Word:
Open up a Word file
Go to the “Tools” menu
Choose “AutoCorrect Options”
Click on the tab “AutoFormat As You Type”
In the list “Replace as you type”, tick the box “Straight quotes with smart quotes”
Mind you, when I did it the first time my MS Word crashed, so make sure you save your work first.
You can look at Microsoft’s solutions for this problem in other MS programmes:
Change curly quotes to straight quotes and vice versa