How to collect ISI Journal Impact Factors

Go to the ISI Web of Science site.
In the top bar, select Journal Citation Reports.
You will now see a list of all journals sorted by Journal Impact factor. To filter the list, use the left hand panel to filter by subject category or select by journal title etc. Once you have configured the filter you need to click on Submit which is at the bottom of the left-hand filter panel.
To change how the Journal data is sorted, click on the column header of the field you want to sort on
You can download the data by clicking on download icon in the top right portion of the web page.