Internet Eater laptop

i have some really weird problem that is really pissing me off , well i just bought a brand new HP laptop, and its seems like he doesnt really like internet because every time i connect to a wireless connection all the wireless server slows down radically and and that makes me and other computers on the same router super lag its like if it eats the connections, so i bought a Mobile Internet hopping it will fix it in a way... but failed , it does totally not i super lag with the mobile internet usb too, the only way i dont lag is when i connect to my wireless connection at home well i do lag but not that much. so if anyone has any idea how to fix this please help me because iam studying in 3D modeling and it hurts my feelings when i lag in class. THANK YOU :confused

 

Kind of hard to help when you describe a phenomenon while not providing technical information of the hardware, the configuration, and how connections are done.