Hi 
Are you downloading the Windows version? If you are using Internet
Explorer is there any chance of using a different web-browser to do
the downloading? Firefox, Opera or anything else tends to be more
reliable than IE so it might be worth experimenting with it. Another
thing that might be worth checking is if you are using wireless then
can you reboot your router?
If you already have tried that sort of thing then it might be good to
try torrenting. It needs you to install a "torrenting client" on your
machine. When you first try torrenting pretty much any torrenting
program is much the same as any other but after you have more
experience you might find you want certain features and not others so
it takes a while before you find the perfect client for your own
needs. People get fairly heated about which is 'best' but usually
they mean which is best for themselves. So i sometimes listen to why
they like thers and if those are featres i want to try then i go with
their choice for a while.
With torrenting you download a tiny file to start with and that keeps
track of which bits of the main download you have.
Regards from
Tom 