"This script can't be run from a regular installation." What does that message mean?
Above was meant to run from CD. No need to panic.

Two things two check if your browser stall :
1) Your nameserver given by your I.S.P , check in /etc/resolv.conf. Is it there. If no, just add.
2) Your mtu. You can set your mtu in /etc/network/interfaces:
Just add your mtu value at the bottom. EX:
iface eth0 inet static
address 192.168.12.28
netmask 255.255.255.0
broadcast 192.168.12.255
gateway 192.168.12.1
mtu 1472

Good luck