You can also use a Network Drive on your desktop, it's very easy and the fastest way to upload any file, I am a web developer and use this method on all my domains and clients domains. Map Network Drive
1. From the desktop, click on Start and then right click on My Computer.
2. Then, click on Map Network Drive.
3. From that screen, click Connect to a Web site that you can use to store your documents and pictures, and then click Next.
4. Click Choose a custom network location, and then click Next.
5. Enter the following in the Internet or network address field:
Example is ftp://ftp.yourdomain.com
6. Enter your ftp username and password when prompted.
Example is username: usedom and password is 123abc you enter these details when prompted
Once you have done the above you can access your ftp for your domain in My Computer at the very bottom of page.
Then all you do is drag and drop your files that you want to upload into your folders on My Computer and it will upload them for you.
If you have any problems don't hesitate to contact me in this thread where i will assist you in creating your desktop FTP client.
This is very secure as your use the same username and password that you do with your CPanel account. Its just much quicker and easier to use.
Hope this help