You can add a setting to the code to prevent popups and also to ensure the deletion is done in the background:
DeleteWorksheets.xaml (6.6 KB) Test.xlsx (8.8 KB)
Dim xlApp As Microsoft.Office.Interop.Excel.Application
Dim wb As Microsoft.Office.Interop.Excel.Workbook
xlApp = New Microsoft.Office.Interop.Excel.Application
wb = xlApp.Workbooks.Open(filename)
xlApp.DisplayAlerts = False
TryCast(wb.Sheets(sheetname), Microsoft.Office.Interop.Excel.Worksheet).Delete()
xlApp.DisplayAlerts = False
xlApp.Visible = False
wb.Save()
wb.Close()