There are security problems with Vista, like there is with every other OS on the market. Research shows that Windows Vista is more security and on average is patched quicker, though this is still subject to arguments, because Vista's market share is so large compared to Linux and OS X the security holes are more likely to be exploited because hackers don't tend to waste their time with an OS that has a relatively low market share, though OS X is making ground as is Linux. So the argument can really go both ways. I would provide some evidence but its late, if you want some though, reply.
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