[Windows Central Question]

Why when I put my usb data stick into my surface pro 4 the wifi disconnects.

[Tejas Javery]

it has something to do with the data stick. as soon as your surface detects it, the stick commands your surface to change connection settings from wireless to that. maybe you can go to settings and check, or device manager. or even network connection settings.

[abhishek singh21]

do scan your usb data stick with windwos defender or nay other third party antivirus app for infection .

also USB 3.0 Hard drive which has been reported/ proven to drop wifi/ bluetooth connection because of radio frequencies that interfere with Wi-Fi and Bluetooth transmissions which is highly unlikely as yours is a data stick / pendrive