outdated: Update and open Uplay. Click "settings". Click "activate product". Follow instructions. Pray!

As of late a lot of people ask how you activate & downlaod your games with the Uplay client, I'll leave this tutorial here:

Requirements

• Uplay must already be installed and you have to know where
• Must obviously have a Uplay key for your game

Preparation

Look in this list, which I stole from reddit and find your game. Note: All Steam keys may not work properly, my Driver:SF doesn't work.

Anno 2070 - 22

Anno 2070 (Steam) - 71

Anno 2070 Beta - 45

Assassin's Creed - 82

Assassin's Creed II - 4

Assassin's Creed II (Steam) - 56

Assassin's Creed III - 54

Assassin's Creed III (Steam) - 102

Assassin's Creed III (Rus) - 103

Assassin's Creed III (Jpn) - 104

Assassin's Creed III (Cz) - 105

Assassin's Creed Brotherhood - 26

Assassin's Creed Brotherhood (Steam) - 57

Assassin's Creed Revelations - 40

Assassin's Creed Revelations (Steam) - 59

Assassin's Creed Revelations -The Lost Archive - 97

Call of Juarez The Cartel (Steam) - 37

Driver: San Francisco - 13

Driver: San Francisco (Steam) - 55

Far Cry 2 - 85

Far Cry 3 - 46

Far Cry 3 (Steam) - 101

Far Cry Blood Dragon -205

From Dust - 30

From Dust (Steam) - 64

I Am Alive - 93

Might & Magic Heroes VI - 44

Might & Magic Heroes VI - 48

Might & Magic Heroes VI (Steam) - 60

Might & Magic Heroes VI Beta - 25

Prince of Persia - The Forgotten Sands - 11

Prince of Persia - The Forgotten Sands (Steam) - 63

The Settlers 7 - 8

The Settlers 7 (Steam) - 61

The Settlers 7 Balance - 27

The Settlers 7 Beta - 16

The Settlers 7 Demo - 17

Tintin - 33

Tom Clancy's EndWar - 83

Tom Clancy's Ghost Recon Future Soldier - 53

Tom Clancy's Ghost Recon Future Soldier (Steam) - 65

Tom Clancy's Ghost Recon Future Soldier - Arctic Strike DLC Pack - 115

Tom Clancy’s HAWX - 86

Tom Clancy’s HAWX2 - 21

Tom Clancy’s HAWX2 (Steam) - 62

Rayman Origins - 80

Shaun White Skateboarding - 20

Silent Hunter 5 - 3

Silent Hunter 5 (Steam) - 68

Splinter Cell Conviction - 2

Splinter Cell Conviction (Steam) - 58

Splinter Cell Conviction - Deniable Ops: Insurgency - 96

World in Conflict - 69

Now the easy part:

• Press [Windows key]+[R]
• A wild dialog box will appear
• Type in the path to your Uplay.exe, this should look like (You should use a) backslashes or b) put it into quotation marks)
  C:/Program Files (x86)/Ubisoft/Ubisoft Game Launcher/uplay.exe
• Press [Spacebar] and then add:
  -upc_uplay_id XXX
• Replace XXX with your game number
• Press enter, Uplay will start and in your games list you can finally enter your key

Comfortable, right?

A last note: if your key is not valid and you try to enter it too often, your whole account will be banned for 3 hours!