Galaxy Nexus uses MTP instead of Mass Storage mode, so you can't mount it as usual.
However, there's an "ADB sideload" option that lets you sideload a ROM from your PC using the ADB command (if you have the drivers installed, in the command prompt window, just type "adb sideload *THE-PATH-TO-YOUR-ROM-FILE*").
Find out more with Google
Originally Posted by throwback1718
$10 paypal to who can help me solve this
We Chinese don't use Paypal
Sent from Google Nexus 4 @ CM11