WinRAR files are corrupted after FTP

In my Windows 2003 server machine I have a winrar or winzip file that i around 3GB.
This zip/rar file is ftped to a unix mahine (HPUX) . FTP is successful. But when it get this file to check if its has been ftped correctly, the file is corrupted.
Is there something wrong that i am doing while performing ftp.
I use the normal ftp command:
ftp -i <machine name>
put <filename.rar>

PLease excuse me if the terms i used are not proper, as I am new to Unix

Thanks,
Maroli

Make sure you did your transfer in binary mode

Yes i have done the transfer in binary mode in bothe scenarios
i.e while using put and also while using get command in ftp
Also i tried using the filezilla to put or get the file in binary mode.. but still no change

One possibility is that your source file may have already been transferred from a remote machine to your current machine in a wrong FTP mode corrupting it.

Try to regenerate your zipfile and retry your FTP in binary.
Make sure your destination has enough free space to receive it.

Do not use mput (which in some bad implementation only transfer the first file in binary and then randomly switch to other inaccurate ftp mode).

The default maximum file size on a HP-UX filesystem is 2 Gb.
Check with the systems administrator whether whether you can create 3 Gb file and whether each and every program involved can deal with a file this big.