U.S. Army is forgoing Windows XP in favor of upgrading to Windows Vista. Instead of upgrading to Windows 7, U.S. army prefers Vista. Windows 7 is not yet out but will come out around august of this year. Why not Windows 7 but Vista? Maybe because Windows 7 is still very new, and the OS may carry critical bugs that nobody has yet discovered. Windows 7 is still very new, and so implementing Windows 7 seems a bit riskier than Vista. Upgrading to Windows 7 is also more expensive than Vista. The U.S. Army figures that Vista is a lot more secure than XP, and so the move to Vista is obvious.
If the U.S. Army is willing to train their soldiers to use Linux, they probably have save a load of cash. At this moment Linux virtually has no virus. Implementing Linux properly, the U.S. Army doesn’t have to fear too much about computer security. You can’t always compare which OS is more secure than another OS, because in the end it’s only matter who is using the OS. You place a person who is really good at Windows but not so good at Linux on Linux, he or she won’t be able to configure Linux to be as secure as Linux should be. The same can also apply to Windows.