Is your computer crashing?(Blue Screen of Death, Lockups, Reboots) or is the file transfer simply not finishing?
If your computer is in fact crashing it is very unlikely the problem is relative to the file transfer itself but a hardware or software error on your computer instead. You can boot into SafeMode with networking (Hit F8 when you boot and choose SAFEMODE WITH NETWORKING. Try the file transfer in this mode and if it does not complete again, it would be safe to conclude there is a hardware issue on your end or an FTP server issue. If it does complete your issue lays in a software compatibility issue in your operating system. Google the word MSCONFIG for guides on how to modify the programs your PC boots up to each time it powers on.
Assuming your "crashing" terminology was incorrectly used in your question and the file transfer just simply isnt finishing it could be any number of things.
#1 Low Hard Drive Space
Your Harddrive could be full. Navigate to my computer, right click on your hard drive and choose PROPERTIES. On the General Tab, click DISK CLEANUP. It will free up a small amount of space and hopefully allow you to finish.
#2 FTP File Trasnfer Quotas
Often FTP servers enable a quota system so clients have to give 1mb for every 10mb they download for instance. Sometimes this can be accidently enabled on the server side with no quota values entered thereby disallowing you to complete the download.
#3 FTP Inadequate FTP Upstream Bandwidth
People often set up FTP servers and do not know all the ins and outs of server setup. There are dozens of issues from Port Forwarding issues to a slow connection from the ISP that can affect how a server can upload data to a client. Often times, people will set up an FTP server on a DSL line with 1500kbps downstream and 756kbps upstream which isnt enough UPSTREAM bandwidth to support more than one download at a time. When multiple requests come in to the FTP server and the server doesnt have the bandwidth to support it's clients, sometimes packets of data get lost and ftp client seems to be forever waiting for that packet. Contact your friend and inquire about any other access issues from users to get a general idea if it is server side before you start pulling out your hair looking at your system.
#4 MSN Skydrive gives you 5gb free space, he can zip the file and upload it there for you to download. Pretty sure Microsoft servers can handle the load :)
#5 Gmail has 7gb storage. He could email them to you.
Dont know if that solved your problem friend but I hope it atleast puts you on the path to resolution.
Good luck