Internet speed really slow in linux but not in Windows

Solution 1:

Please check to see if two possibly conflicting drivers are loaded:

lsmod | grep rtl

If you find that both rtl8192cu and rtl8xxxu are loaded, then blacklist one:

sudo -i
echo "blacklist rtl8192cu"  >>  /etc/modprobe.d/blacklist.conf
exit

After making this change, reboot and let us hear the result.