How many O.W.L.S did Harry Potter receive?

Answer 1

Harry got seven O.W.L's. One Acceptable, five Exceeds Expectations and one Outstanding. He failed two.
Astronomy - A

Care of Magical Creatures - E

Charms - E

D.A.D.A - O

Divination - P (failing grade)

Herbology - E

History of Magic - D (failing grade)

Potions - E

Answer 2

As many as Harry, minus the ones Umbridge gave Harry in The Order of the Phoenix and plus the one Snape gave Ron for attacking Malfoy.(when his spell backfired because of his broken wand and made him barf slugs)

Answer 3

During his time at Hogwarts Harry received the following detentions:

• During his first year he was caught out of bed in the strictly out of bounds Astronomy tower at midnight (after getting rid of Norbert. His detention was to help Hagrid find the injured unicorn in the Forbidden Forest.

• At the start of his second year, Harry was immediately given detention for flying an illegal car to Hogwarts and being spotted. He was made to sign Lockhart's fan mail.

• During his fourth year, Harry was given detention for shouting at Snape after he unfairly favoured Slytherin in a duel that left Hermione with teeth that kept growing. He was made to pickle rats brains.

• In his fifth year, Harry received three weeks worth of detention from Umbridge for calling her a liar, loosing his temper and spreading "lies" about Lord Voldemort. He was forced to write "I must not tell lies" with a quill that cut his hand open and used his blood for ink. He was later given another weeks worth of detention for attacking Malfoy but Umbridge over-ruled it an changed it to a ban on Quidditch.

• In his sixth year, Harry was once again given detention for being cheeky to Snape. He was made to sort out rotten Flobberworms from good ones without protective gloves.

• Near the end of his sixth year, Harry cast the Sectumsempra curse on Draco Malfoy, seriously injuring him, and was given detention for every remaining Saturday in the year. He was to clean out Filch's punishment files.

Answer 4

Countless. (And a few of them were actually deserved;)