It seems that you didn't install the proper drivers on your PC as it doesn't recognize it.

Sent from my LG-P880 using XDA Premium 4 mobile app
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|| LG Optimus 4X HD (P880)
|| Android Version 4.4.2 Kitkat
|| Recovery TeamWin Recovery Project 2.7.0.0
|| Kernel Iodak 9.95 (patiently waiting for v10 )
|| Rom Version Beanstalk 4.4.275 ported by Ecto

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