Please let me know a efficient way to transfer files from a solaris to a windows machine. Total size of data is 800GB.
use samba to share it over from solaris </usr/local/samba/lib/smb.conf>, then you do a compress/transfer or use any tool like coreftp(will take super long) 
Hi PingMeBack!
Use WinSCP (uses SSH) free software.
cifs or nfs is a lot faster then using scp to copy 800gb of data. so if it can be slow, scp might be an easy choice and cifs or nfs might be the faster choice.
(for nfs you need extra tools to teach windows nfs)