Define a Duplicate Before Removing Rows in Excel
A repeated customer name does not necessarily mean a duplicated order. One customer can place several orders, and two people can share a name. Decide what makes a record unique before using Excel’s Remove Duplicates command.
For example, a fictional order list might use Order ID as its key, while a line-item list needs both Order ID and Line Number. Write down that rule and examine several repeated cases. If you cannot distinguish a duplicate from a legitimate repeat, pause deletion and clarify the data model.
Preview before changing the list
Keep the original workbook and work on a separate copy. In desktop Excel for Windows, conditional formatting can highlight duplicate values for inspection. That is useful for finding candidates, but a highlighted name by itself does not establish a duplicate record across several columns.
When the rule is clear, select the complete intended range and open Data, Remove Duplicates. Review the selected columns: they determine which fields Excel uses to compare records. The operation removes duplicate data, so this is a content change rather than a viewing filter.
If two candidate rows differ in a field you need to preserve, resolve that conflict before removal. Do not discard one merely because the chosen key matches.
Account for the rows that disappeared
Record the starting and ending row counts and inspect the retained version of several duplicate groups. Compare meaningful totals where appropriate, while remembering that a repeated amount can be legitimate.
Microsoft notes that its duplicate and unique counts can include empty cells or spaces. Treat the completion message as an operation report, not proof that the final dataset matches your business rule.
Save the cleaned result under a distinct name and retain the untouched source until the result has been accepted. Keep the duplicate rule with the file so the next person can understand why rows were removed and reproduce the decision on a later export.
References: Microsoft: finding and removing duplicates.