Try switching your wireless card off for a start - disable it - most laptops have a switch

Could be cheap usb cables between your soundcard and laptop

Could be your hard drive not grounded - I have the same issue with my shitty novation Nio soundcard and digital buzz that seems to be related to the HD motor

Try one of these

ART DTI Dual Transformer / Isolator | DV247

Or behringer do a cheaper one

Behringer MICROHD HD400 Ultra-Compact 2-Channel Hum Destroyer | DV247

No guarantees but I know a few people who have them and they work for them