every common utility software need WinXP SP3 as minimum, its light [means needs less RAM and CPU than Win7 ], and most of the games and internet softwares will work for home users,
for business, they dont need to change OS in every 2-3 years, they dont need to waste money on this, because their business computer working great with XP, why they need to learn some new things and waste some money ?? so its still running, running.....
here in india, banks still running with WinXP and QuickHeal antivirus,...... some days ago, i noticed that when i was talking with a Bank Branch Manager and he making some entry in browser, from taskbar QuickHeal 2/3 Popsup comes with message something like this " **** file looks like a spyware, and so quarantined..." , and he didn't even noticed, and doing his online work as usual...
another thing, 2-3 years ago when repairman trying to fix a ATM i noticed that ATM machine was still running with Win2000 !!!!