When you open a CSV file in Excel by double clicking or opening the file, the data may appear corrupted or unreadable. 
This issue occurs because the CSV file is saved as Unicode text, but Excel reads CSV files in non-Unicode by default.

To direct Excel to use Unicode on your exported CSV reports:

1.     Start Microsoft Excel

2.     In Excel, click the Data tab, and in the Get External Data ribbon/panel, click From Text .

3.     In the Import Text File dialog box, in the lower-right corner (to the right of the File name box), select Text Files (*.prn;*.txt;*.csv) as the file type, browse to the location where you exported/downloaded the CSV file, and then click Open (or Import).

4.     In the Text Import Wizard - Step 1 of 3 dialog box, select Delimited, and from the File origin drop-down list, select Unicode (UTF-8). 
In the Preview box, make sure that your Unicode text displays properly, and then click Next.

5.     In the Text Import Wizard - Step 2 of 3 dialog box, in the Delimiters section, make sure that only Comma is checked, and then click Finish.

6.     In the Import Data dialog box, select New worksheet (or Existing worksheet if you have one), and then click OK.

7.  Lastly, save the Excel spreadsheet.