* Three things are inevitable in life: taxes, death and that Microsoft's launch dates will slip. The latest victim of this law is Microsoft Vista, the successor to the Windows XP operating system. Vista was expected a couple of years ago, but it has been dogged by delays. Just weeks after Microsoft said Vista was on track for a pre-Christmas launch, the company now says the consumer version of Vista won't be out until January 2007, although some believe spring 2007 is more realistic. Vista will be more robust, more secure and more flexible than Windows XP says Microsoft, but whether that's enough to persuade schools to upgrade to it remains to be seen.