Unlocking bootloader adb device offline error

I tried restarting phone and pc, turning on and off usb debbuging and installing pdanet. It did not help.
What shows first command prompt:

C:\cock files\android-sdk-windows\platform-tools>adb devices
List of devices attached
adb server version (25) doesn't match this client (36); killing...
* daemon started successfully *
3204a3a72102916d device


C:\cock files\android-sdk-windows\platform-tools>



What shows second command prompt:

C:\Users\john\Desktop\r5-galaxynexus-superboot>adb-windows reboot bootloader
adb server is out of date. killing...
* daemon started successfully *
error: device offline

C:\Users\john\Desktop\r5-galaxynexus-superboot>



Please help.