my phone is not connecting to laptop

[AC Question]

I have le 2 phone which was i bought in December end untill before few days my phone was connect to laptop bt yesterday i try it doesn't work n i was try on my frds laptop also
I was change cable also
In laptop shows usb not recognised
Plz give me solution

 

[B. Diddy]

Welcome to Android Central! Check the phone's microUSB port for any debris -- use a can of compressed air to blow it out. Also, clean the contacts using a Q-tip dipped in rubbing alcohol.