Large file copy & past with 2 WinXP PCs

I have two WinXP HE PC tied together with a Linksys EtherFast Router and a USB link (Signal strength is excellent. I want to copy a 700 MB (CD-R) size file from the laptop to the desktop. I am running ZoneAlarm firewalls on both ?machines. I get about 1/3 done, and one of the machines disconnects me […that domain is not available, etc]. Any way to do it with Zmodem or FTP and get it done in one shot? How about restarting part way through were connection was lost? any thoughts? Thanks, Tom Killeen