You have a csv file and
1. You double click it, the file will be opened directly in Excel.
2. You opened the file from File > Open but still the file opens directly in Excel.

The solution is to change the extension of file from csv to txt. Hence, if you are having a file name myfile.csv, change is to myfile.txt. Now, you should open the file from File > Open method and Text to Columns Wizard pops up.