I'm unsure what you meant by security hits but the most common is that the new owner installs a firewall and has reporting turned on. Suddenly they think their machine is under attack and they also may think XP is why. Such is not so.
XP does a lot more and items moved around so the initial view is that it's less friendly. I will agree it seems so because accounts and proper setup is no longer optional.
Give it some time to soak in and find your way around.
About the old machine. Given hard disks (new) are from 50 to 100 bucks, I wonder why a new drive was not fitted.
I had my windows ME for 6 years, and managed with help from this forum to sort out all problems. It was running very well, until 2 weeks ago when I got a notice saying it could not access hard drive. I consulted a couple of computer techno's who told me to ditch it, unless I wanted to spend money on it trying to access the hard drive. I went out the following week and purchased an XP, and I am amazed at how many security hits I am getting. Also I find it is not as user friendly as my ME. So to all you people out there who are running an ME just be very grateful that you have such a wonderful little operating system. Thanks for all your help guys.