I would unhesitatingly recommend a hardware firewall.
£50 gets you a firewall / switch (4-port) / router from Netgear / D-link / Vigor etc.
A further £25 or so gets Wireless and / or printer port.
Network multiple PCs, all with access to the Internet safely behind a hardware firewall for not much more than the cost of the software firewall - and nothing to slow down your PC.
No-brainer for me!
SD