Why does William Stryker say he gave Wolverine claws even though he had them way before?

This is a perfectly acceptable communication if he is only speaking figuratively. "Claws" doesn't mean only physical, literal claws, it is a metaphor for the ability to be violent, to be competently violent. He might very well have said the same thing if he had armed him with a rifle.

And, if we examine these movies closely, Wolverine becomes physically capable of even more extreme violence. Before he merely regenerated, now he can tear open a metal vault to get to you. Before, you could cripple him for minutes by breaking his bones, now they simply do not break and he does not slow down.

The "claws" metaphor is fairly widespread. He would have used the word "claws" even if Wolverine instead had a stinger, or fangs, or horns.

The X-Men films typically follow mainstream knowledge of the comics. Wolverine wasn't known to have bone claws by the general audience, so they didn't mention it. The Bone Claws reveal was only done in 1993, recent compared to Wolverines entire history. He's typically depicted as thinking that he gained claws from the Weapon X program.

Wolverine has always had memory issues. He normally doesn't know who he really is, or his childhood. Readers didn't find out he was James Howlet until the Wolverine Origin comic in 2002, which was then used as the basis for the Movie. That revealed that Wolverine always had bone claws as far back as childhood, and Sabertooth was his blood brother.

X2 was released in 2003, so incorporating anything from 2002 into the script would have been unlikely.

Notice that Wolverine is confused in Days of Future Past, when he wakes up the 60s and has bone claws instead of metal. His memory was erased at the end of Origin by an Adamantium bullet to the brain, courtesy of Striker. Xavier is shown to be working to help Wolverine regain his memory through out all the movies.

Assuming all of this is in continuity, Stryker has been shown to be quite smart, cunning and willing to use people, and having known Wolverine suffered memory loss, his wording can be assumed to be an intentional omission. He admits what Wolverine already knows, and doesn't volunteer what he doesn't.

The X-Men film series has an ever-shifting canon. With the first two films, it is established that a number of handheld adamantium guns were used over an extended period of time to graft the metal to Logan's skeleton. With X-Men Origins: Wolverine, however, the scene was changed to show a number of automated rods simply impaling Logan's body and covering his skeleton, including the claws, in adamantium.

With X2, it can be inferred that Logan did not have the claws already, so this was by Stryker's doing. With X-Men Origins: Wolverine, however, the procedure was done to make Logan formidable enough that he could successfully combat Victor. So, if we were to smooth over this continuity discrepancy, Stryker's line in X2 simply means that he gave Logan the proper means to match his natural ferocity.

You didn't have to take that dialogue that literally. He doesn't mean that he didn't have claws before, but he means that he didn't have the Adamantium claw before.

So he means that he was an animal way before that experiment and he just gave a weapon to an animal.

Wolverine didn´t have claws back then!

His mutant powers were self healing, and heightened smell.That was a retcon done by Marvel close to the Wolverine movies in the 2000s

Here a link:

http://www.thegeektwins.com/2009/05/i-hate-wolverines-bone-claws-too.html#.WVW5qus1-Uk