From ModMyiFone - Wiki
Here's an easy approach on using SSH on Windows.
NOTE: You need a jailbroken iPhone/iPod Touch, with OpenSSH and BSD Subsystem installed on it. (You can get both from Installer.app)
1. Get WinSCP from here.
2. After installing, launch WinSCP.
3. Connect to your Wi-Fi network from your iPhone/iPod Touch.
4. Now launch WinSCP
5. Now under host name, type your iPhone/iPod Touch's IP address. (To find your IP address, just go to Settings -> Wi-Fi -> and click on the blue network next to the network you're connected to)
4. Don't fill in anything else, and press login.
5. It might display an error message like this:
Click Yes.
6. Now it'll ask for a username and password. Try these two combinations. Depending on your firmware, one of them will work.
Username: root
Password: alpine
Username: root
Password: dottie
7. You're in! Now you have full access to your iPhone/iPod Touch on your computer using Wi-Fi.
You can also install Services from Installer.app, to switch off SSH when you don't need it.