I can confirm the issue is happening as well. Same exact replication steps.

Mine seems to be working okay.
I have to alt+tab to use my other monitor.

Rabbit, an inability to use another monitor is not an issue; alt+tab does work fine.

Reread my description.

Experienced everything described.

Running on a dual screen setup and I can confirm that the cursor moves to the second screen. But clicking outside the primary monitor (read: where the game us running) bounds seems only to be possible when you work with systems that require a mouse cursor such as the inventory. As soon as you close those clicking outside of the monitor bounds is not possible anymore or at least does not make you loose focus on DayZ or worse would minimize the game.
Still I would like the mouse cursor to be locked to the main screen and possibly make it an option.

I am also experiencing this problem, very frustrating.

Yip yip yip, I have to make sure all explorer windows/programs are closed on my second monitor before I play the game, otherwise I might accidentally click them and lose focus, thus minimising the game.

Rusk has mentioned an interesting point there though, the game not losing focus so long as you're not in an inventory/cursor mode in the game. I've yet to test this.

Was about to create this very ticket.

I use two monitors and my mouse does not lock on Dayz game and end up lost on my 2nd monitor.

I was about to create a ticket. This isuses is driving me insane. I'm on Windows 7 x64. Using Dual Monitor. I was having the exact same issue on Windows 8 x64 with different hardware. I'm pretty sure everyone with dual monitor have this issue.

If you press "tab" to check your inventory the mouse cursor will often ends up on your other monitor. This is getting really annoying and almost game breaking IMO because if I click the mouse button it will lose focus and alt-tab the game. It always take me a while to find my cursor after pressing ESC or using the Inventory. Please, make this a priority.

Yup, having the same issue since Day 1, would love a fix because it is very annoying to try to click in game and end up on the desktop getting smashed by zombies in game.

Please fix this problem. It happens without even forcing the cursor to show in-game.

Had this problem since I first started up the game and it's quite annoying.

Hello InTheCatBoxAgain,

Thank you for sending us your feedback regarding this issue. Unfortunately, this problem is a known issue that has previously been reported.

Closing as duplicate of #825.

Regards,
JStewart