Setting up two Magic Jacks on a single computer for a two-line phone system is feasible and has been done by many users. However, there are a few considerations to keep in mind before proceeding with this setup, especially with Windows XP and the upcoming upgrade to Windows 7. Here are some key points to consider: 1. Compatibility with Windows XP and Windows 7: - Magic Jack should work with both Windows XP and Windows 7. However, it's important to ensure that you have the necessary drivers and software updates for the Magic Jack to work seamlessly on both operating systems. 2. Bandwidth Usage: - Magic Jack uses an internet connection to make calls, so it will consume bandwidth when in use. Since you have a Business T1...