I got it: put VSync on "enabled" in your options - this will remove the 0xc0000005 error,

but it will still crash, but less and without an error message

I got exact the same error, also: exception "unknown software exception" (0xc0000005) ... 0x00e35f27, I also got Windows Vista (64 bit), and at me it crashes after 5 min. just back to desktop

My graphic card is the old GeForce GTX 285 (Nvidia drivers updated)

Note Update:
it seems it works now, atm. But I don't know why.
That's what I did:

• "enabled" VSync in DayZ grafic configuration
• changed my "German" language to "English" in DayZ.cfg
• did the command: "bcdedit.exe /set nx AlwaysOff" (run cmd as Administrator) (undone/default: "bcdedit.exe /set nx AlwaysOn")
• and edited something in regedit, but I don't think it is important