My other computer on the network is an Acer desktop that was purchased just before Vista was released. There were some hardware problems at first and the machine was shipped to Texas for what turned out to be a warranty covered hard disk replacement. Other than adding a gig of memory to bring the total up to two there has been no work needed and the computer has been a pleasure to use. All the updates have been faithfully installed.
I have Norton 360 on it as part of a possible user count of three under the license.
I keep asking myself if it is worth it to invest in a Windows 7 or 8 upgrade? According to the Microsoft upgrade advisers, either version will work with minimal problems. Most of my software is open source like Open Office and Lazarus and can easily be reinstalled. Norton has to have an upgrade path and Roboform should be upgraded anyway.
I did keep using Windows 95 far past its support termination with no great problem other than the fact the software itself was acting flaky with some of the newer programs I tried to run on it. As I recall I even used AVG as an antivirus program on it and had no problems.
I still am sitting on the fence with this though. I would love to try Windows 8 even though the monitor is decidedly pre-touchscreen. Even Windows 7 might be interesting because of the better functioning with newer software like IE.
I suppose what I will do is keep worrying as long as I can without doing anything and then when the pressure builds sufficiently something will be done.