How we can put an excel file residing on our computer to an auto update when some data is changed in excel file
The data sources created using files- uploaded from your computer, cannot be refreshed at specific intervals. You will have to re-upload the file from your computer to see the latest data.
So, for your requirement (I understand that you want the data source to pick up the changes on refreshes), we recommend you saving the files (that you want to use as your data source) in dropbox or box or google drive. And then using one of these connectors (dropbox/box/google drive) to create data sources with the file of your choice.
Hope this is helpful!