@Louisaplouisapot
The csv file is probably OK, but I suspect there is a discrepancy between the list separator character on the source computer and the target computer. For example, if the source computer uses a comma as list separator, it'll place that between the data. If the target computer uses a semicolon as list separator, it won't recognize the comma and dump everything into the first column.
You can either ensure that both computers use the same list separator (it is a system setting), or use Data > Text to Columns to split the data.
