Please don't say SQL is difficult
SQL is good for a great many things but it is essentially set oriented. You have to identify a set. The "set" is the "5" duplicates. I think you missed the point of the question. The OP has duplicate data in a table that he needs to clean up. The duplicates are not caused by a join, which could be a logic problem or a simple misunderstanding of how 1-m relationships work. This is an actual, physical problem. He wants to get rid of 4 of the 5. How does he identify which 4 of the 5 "identical" records to delete? A TimeStamp won't help. That isn't data that is easily accessible or even understandable. To use it, you would need to know how each value relates to all the other values in the set of duplicates. All we know about a TimeStamp is that it is unique, at least within the table. An autonumber that is sequentially assigned is the most viable discriminator but the table may not have one or it may be randomly assigned which won't help. You suggested adding an autonumber. OK, but was that only because you have to disagree with my suggestion?
If we believe the problem statement, these are actual, physical duplicate rows. How did they get there? How do we prevent that in the future? How do we get rid of the existing dups?
The third question is where the OP is starting. First we get rid of the dups. My solution solves two of the three questions at once. You can tackle them all separately if you choose. You can modify the input table, you can create beautifully formatted, colorful, complex subselects 4 levels deep, or, you can use my suggestion which in one step fixes the existing data and prevents future duplicates from being added and uses a simple append query with no criteria. It takes advantage of how Access SQL append queries work. I guess my suggestion is just too simple.
As to "how did they get there", the OP will need to look at how the data is added to the table. If it is appended from an external source, my proposed solution keeps on working because the append query will discard the "duplicates" as long as the indexes were correctly defined. If the records are added one at a time using a form, proper validation will give the user an understandable message and let the user fix the data before it is saved.