Quite often i will use Microsoft Excel to edit CSV file. But sometimes you may find garbled characters in the opened file and it is caused by the file encoding.
For example, Excel could not view UTF-8 file. So if you got a CSV encoded in UTF-8, you need to convert it to ANSI encoded. This could be done by opening the CSV file in Notepad and then save it as new file in ANSI encoding.
The newly saved file could be opened in Excel now.