Reading thousands of emails in eight days still seems like a lot of work.

That number got even smaller relatively quickly. Many of the emails were copies of messages that agents had examined earlier while investigating Mrs. Clinton and her aides. Again, it’s not clear how many were duplicates, but law enforcement officials say it was a substantial number. Filtering software can ferret out duplicates from far larger databases than Mr. Weiner’s hard drive. That could have sped up the review, because the duplicates didn’t need to be examined again, but F.B.I. employees would still have had to personally vet new emails.

Was there classified information on the computer?

It is not clear, but that was never the most pressing question. From the beginning, officials said it would take an extraordinary discovery to change their conclusion that nobody should face charges in the case. Prosecutors and agents knew that classified information had been improperly stored on Mrs. Clinton’s server. The F.B.I. director, James B. Comey, called it careless but said it did not rise to the level of a crime. Simply finding more classified information would not, by itself, have changed that conclusion.

The F.B.I. has not said what was in the newly discovered emails, but records previously released under the Freedom of Information Act show that Ms. Abedin’s inbox contained mostly scheduling discussions, routine office chatter and the occasional instruction from Mrs. Clinton to print something.

Why didn’t the government tell us this would only take a week?

The F.B.I. was reluctant to predict how long the review would take, repeatedly trying to lower the public’s expectation that it could finish before Election Day. Even though the number of emails seemed manageable early in the week, there was a chance that agents would discover something along the way that would require extensive follow-up.

Attorney General Loretta Lynch and Mr. Comey assigned dozens of agents and analysts to the effort, including investigators who had originally worked on the case. Dozens worked around the clock for a week. Law enforcement officials said the review was completed Sunday morning.

What now?

While the F.B.I. investigation is closed, Republican members of Congress have said they will not stop looking into Mrs. Clinton’s actions. Representative Jason Chaffetz of Utah, the chairman of the House Oversight and Government Reform Committee, has promised to investigate Mrs. Clinton and said that inquiry could take years.

If Democrats win control of the Senate on Tuesday, they could open an inquiry of their own — into Mr. Comey’s handling of the email investigation.