You can get an instant backup of all your data in spreadsheet format at any time.  To do that, just go to Tools & Reports > General Reports > Sage Export.

On the next screen, Enter in the Start Date as a date before you started using Tally (i.e. 01/01/1970) and todays date as the End Date > Click Re-Run Report > Click the four Download buttons to download spreadsheets containing all your account data.