The simplest way is to install an FTP service on your EC2 host, open port 21 in the firewall and Security Group, and use your FTP client of choice on Win7 to push the data up.
For bonus points, use SFTP instead over port 22. You don't mention the EC2 host OS, but if it's Windows you can use msftpsvr on the host and FileZilla on Win7.