Windows 7 is a really good OS, fast, stable and can find 98% of hardware out there. Windows update actually works and installs drivers with no problems.
Only hardware that wont work is really old legacy stuff, but then if you are still trying to use 10 year old gear on a PC you're crazy (sounds strange coming from an Amiga user ;-)).
If you must have XP it has an XP mode (virtual machine basically) works 100%.
Vista was a dog, I beta tested that for a corp enviroment for awhile. So many issues, it was basically a Windows ME.
Windows XP is fine, running that at work in a military environment with no issues. Although hardware companies will slowly drop support for XP. Which is as it should be. The OS has reached it's EOL.
Android is a good OS, it's starting to really evolve. OSX is okay, but I found it limiting and it's no good in a corp world. Great for home use however, although the limiting factor there is gaming.
Ubuntu is also good, although some games I have wont run under it. Other than that it makes a good OS at home. Although no good for work at this point in time.
We need to run a stable, supported OS on base as you can imagine if it went wrong it could be a bag of giggles when a ship takes out a friendly ;-)
