This task was so easy that I couldn’t find it in the first place.
Condition is, I don’t want to remove duplicate cells or rows because I like to see first what is duplicate to delete myself.
Under “Data” there is a “Remove Duplicate” command which deletes my duplicates. And that’s what I don’t want to archive.
Plan B: Highlight my duplicate Cells:
1. Select the columns or rows where you want to find the duplicate cells.
2. Go to the “Home” Tab and click on “Conditional Formatting” -> “Highlight Cells Rules” -> “Duplicate Values”
3. In the “Duplicate cells that contain” pop-up select “Duplicate” and the highlight color. And don’t forget “OK”
There you go.