Q. I am going to start college in the fall and I need a laptop. Uncle Jim, who is a Mac addict, is making an argument for a MacBook with Parallels 3.0 and Windows XP installed. He said that way I would have the best of both worlds. My mom is looking at the price. She said we could get a PC for less money but I want to make sure we're making the right decision. If money is not an issue, what is your recommendation?

A. Both your mom and your uncle are correct. You can indeed get a decent laptop from Dell or Hewlett-Packard for less than the $1,099 that Apple's least expensive Mac laptop, the MacBook, costs. But, in my view, the Mac has a better, faster operating system, better built-in software, and is far less likely to expose you to viruses and other malicious software. Plus, the MacBook itself is a sturdy piece of hardware. And there's a very good Mac version of Microsoft Office that is fully compatible with files created on the Windows version.

Your uncle is also correct that Macs can run Windows, and Windows software, quite well. However, the solution he suggests, using the Parallels software, which enables Windows use on a Mac, will add significantly to the price. Parallels costs around $60, and you also must buy a full, boxed edition of Windows XP or Vista. While prices for Windows vary, this full version (not an upgrade version) of XP can cost nearly $200, and Vista typically costs more.

So, if money really isn't an issue, I recommend the MacBook. But, since that is rarely the case in real life, you might want to weigh the cheaper alternatives more carefully. Or, if you do buy the MacBook, I'd hold off on the Windows installation until and unless you find you need Windows programs that have no counterpart on the Mac. The average undergraduate likely won't.

Q. I am dissatisfied with my Internet service provider and I would like to switch to another one. If I switch, can I keep the same email address? Do I have to keep paying the old ISP if I switch and keep the email address?

A. It depends on your ISP. If it is America Online, you will be able to drop AOL as your ISP and continue to use your aol.com address, regardless of which provider you use to access the Internet. But, in most cases, if you are using the email address provided by your ISP, you will have to relinquish it. However, I would suggest you consider obtaining an email account that isn't tied to an ISP, so that, if you have to change ISPs again, it won't disrupt your email. Among such email-only services are Yahoo Mail, Microsoft's Windows Live Hotmail, and Google's Gmail.

Q. Your column last week concerned a navigation device called Dash Express that transmits the speed and location of your car to the company for traffic information purposes. But couldn't this capability also be misused by the company to track a driver's whereabouts, or even help issue speeding tickets?

A. Theoretically, yes. But the company, Dash Navigation, says it retains no personally identifiable information on its servers, and merely collects traffic data from participating cars anonymously. A company spokeswoman says: 'If the FBI came in and asked us to find someone, we would have no way of locating an individual car.'

专栏作家莫博士就有关如何选购笔记本电脑、电子邮件地址的保留以及Dash Express个人信息保密问题答读者问。

问：我秋天就要上大学了，想要买一部笔记本电脑。我的叔叔吉姆是个苹果电脑发烧友，他极力主张我买MacBook，装上Parallels 3.0和Windows XP操作系统。他说这样我在软硬件上就都是最好的了。我妈妈比较了价格。她说我们可以少花点钱，买台其他牌子的电脑，不过我想确保我们能做出正确的决定。如果钱不是问题的话，你推荐哪款电脑呢？

答：你的妈妈和叔叔说的都没错。最便宜的苹果(Apple)笔记本电脑MacBook要1,099美元，你不需要花这么多的钱就能买到一部不错的戴尔(Dell)或是惠普(Hewlett-Packard)电脑。不过，我认为苹果电脑的操作系统更好、更快，内置软件也性能更佳，而且受到病毒和其他恶意软件攻击的可能性要小得多。除此之外，MacBook本身也很结实耐用。还有一套Mac版的Microsoft Offic办公软件，这套很好用的软件可以与Windows版Office软件创建的文件兼容。

你叔叔另一个正确的地方是苹果电脑确实能良好地运行Windows操作系统和Windows应用软件。不过，他建议的方法──在苹果电脑上安装Parallels软件，以便运行Windows操作系统──会使价格大大提高。Parallels软件价格大约为60美元，你还必须到店里买套完整的Windows XP或Vista。由于不同的Windows操作系统价格不同，Windows XP完整版（而非升级版）的价格可能会接近200美元，而Windows Vista的价格通常还要高。

广告因此，如果钱真的不是问题的话，我建议你买MacBook。不过，在现实生活中，常常还是要权衡价格的，所以你可能需要认真地考虑一下价格较低的电脑。不过，如果你买了MacBook，我建议你别装Windows系统，除非你需要的Windows软件没有相应的Mac版软件。普通的大学生很可能使用内置软件就足够了。

问：我对自己的互联网服务提供商(ISP)很不满意，我想换一家。如果我换了ISP的话，我还可以保留原来的电子邮件地址吗？如果我想保留的话，是否还要向原来的那家交钱？

答：这取决于你的ISP。如果你现在的ISP是美国在线(America Online)的话，你可以取消服务，而仍然保留你的aol.com电子邮件地址，无论你新的ISP是哪一家。不过，在很多情况下，如果你使用的是ISP提供的邮件地址，你将不得不放弃它。我建议你申请一个不和ISP挂钩的电子邮件帐户，这样，如果你必须再次换ISP的话，你的电子邮件不会因此中断。这类电子邮件服务包括雅虎公司(Yahoo! Inc.)的Yahoo Mail、微软(Microsoft Corp.)的Windows Live Hotmail和谷歌(Google Inc.)的Gmail。

问：上周你的专栏中讲到了一种名为Dash Express的电子导航设备，能够将车的速度和位置上传给Dash Navigation公司，进行交通信息处理。不过该公司会不会滥用这种能力来追踪驾驶者的位置，甚至帮助开超速罚单？

答：理论上讲，是可以的。不过，Dash Navigation表示，它在自己的服务器上并没有保留任何能够识别出个人身份的信息，只是以匿名的方式从参与的汽车中收集交通数据。公司的一位发言人说，如果美国联邦调查局(FBI)来公司要求我们找到某个人，我们也没法找到某辆特定汽车的位置。