Eternal Sunshine of the Spotless Hard Drive
There's no other major item most of us own that is as confusing, unpredictable and unreliable as our personal computers. Everybody has questions about them, and we aim to help.
Here are a few questions about computers I've received recently from people like you, and my answers. I have edited and restated the questions a bit, for readability. This week my mailbox contained questions about completely erasing a PC, installing Verizon's Fios Internet service, and using a Firefox Web browser on an iMac.
If you have a question, send it to me at
mossberg@wsj.com, and I may select it to be answered here in Mossberg's Mailbox.
Q: I am giving my PC to my sister and I would like to completely erase my files from the hard drive. How can I do this?
A: What you need to do is wipe out the files in a way that is more thorough than merely deleting them in the standard manner. This process is often called "wiping" files, and makes the files impossible, or at least very difficult, to recover. It works by overwriting the portion of the hard disk formerly occupied by a file's data with nonsense characters.
You could format the disk, but that also would wipe out the operating system, which would require your sister to buy and install a new copy. So you need a program that wipes out only the folders and files you target. On an Apple Macintosh, this capability is built in. You just move the files to the trash and then select "Secure Empty Trash" instead of the usual "Empty Trash" command.
On Windows, you need add-on software. There are many programs that do this, but one that I have tested and can recommend is Window Washer, which is available at webroot.com for $30. You can find others by doing a Web search for "file wipe" or by doing a similar search at download.com.
Q: If you install the new high-speed Verizon Fios Internet service you recently reviewed, do you have to upgrade your wireless network?
A: It depends. Verizon will supply you with either a wired or wireless router, the box that transmits your Internet connection. If your current Wi-Fi network is slower than the maximum speed of Fios, you should take the Verizon wireless router. For instance, if you have the 15 megabits per second version of Fios, but only have a Wi-Fi "b" type network, which works at a maximum of 11 mbps, take the Verizon wireless router and allow Verizon to install it in place of your current one. The Verizon wireless model works on the newer "g" flavor of Wi-Fi, which can handle speeds of as much as 54 mbps.
You also will need to make sure that all the PCs you are planning to connect wirelessly to Fios have "g" type Wi-Fi connections. If even one of them has "b" equipment, it will drag down the whole wireless network to the lower speed of "b." (This doesn't affect wired connections to computers.)
However, if your wireless router is fast enough, and you like it, you can keep it with Fios service. I did, because I am using the Belkin "Pre-N" router, which has better speed and range than any "g" router I've seen. I just took the plain old wired router from Verizon and plugged my Belkin wireless router into it. Others have dispensed with the Verizon gear entirely, and just plugged the Fios cable directly into their wireless routers. The main downside here is that Verizon says the routers it installs contain special software that can help diagnose Fios problems.
Q: Can I use the Firefox browser on my iMac? I am running version 9.1 of the operating system.
A: Unfortunately, no. While Firefox works on the Mac, it requires the newer Apple operating system, Mac OS X, which was introduced in 2001. Firefox requires Mac OS X 10.1, at a minimum. Your computer has an entirely different, older, and much less capable operating system, which Apple has pretty much abandoned.
By the way, for Windows users, Firefox requires Windows 98 or higher. For both platforms, there also are minimum hardware requirements. Firefox also runs on the Linux operating system, and has minimum requirements on that platform as well. Requirements for all platforms are at:
www.mozilla.org/products/firefox/system-requirements. 如何彻底删除文件
在我们大多数人拥有的大件电器中，再没有什么比个人电脑更令人费解、更变幻莫测的了。每个人或许都有些关于电脑的问题，而《莫博士信箱》将为您提供帮助。
本周我将回答读者有关彻底删除文件、Fios高速互联网服务和使用Firefox浏览器的最低系统配置等问题。
问：我正要把自己的个人电脑送给我的妹妹，我想把自己的文件从硬盘上彻底删除。我该怎么做？
答: 你所要做的就是以一种更彻底的方法清除文件，而不是以通常的方式仅仅删除文件而已。这个过程通常叫做“彻底清除”文件，它可以使文件不可能、或者至少非常难以复原。它的工作原理就是：用乱码覆盖原先被文件数据占据的硬盘部分。
你可以对硬盘格式化，但这样一来，操作系统也会被清除，你的妹妹就必须购买并安装新的操作系统。因此，你需要一个只清除目标文件夹和文件的程序。在苹果Macintosh电脑上，这个功能是内置的。你只要把文件移至垃圾箱，然后选择“安全清空垃圾箱”、而不是通常的“清空垃圾箱”命令就可以了。
在Windows电脑上，你需要额外安装软件。能实现这种功能的软件很多，但我测试过并愿意推荐的一个是Window Washer，这款软件在webroot.com上有售，售价30美元。你也可以通过网上搜索“文件清除”或者在download.com上搜索类似的关键字找到其他具备这种功能的软件。
问：如果安装你最近测试的Verizon Fios高速互联网服务，必须对无线网络进行升级吗？
答：这要视具体情况而定。Verizon将为你提供有线或无线路由器，用来建立你的互联网连接。如果你目前的Wi-Fi网络速度比Fios的最快速度要慢，那么你应当采用Verizon无线路由器。比如说，如果你的Fios速度为每秒15兆，而Wi-Fi网络只是最高速度为11兆的“b”类，那么就采用Verizon无线路由器，取代你目前使用的。Verizon无线路由器可以在更新的“g”类Wi-Fi网络上运行，速度可以达到每秒54兆。
你还必须确定你计划无线接入Fios的所有个人电脑使用的都是“g”类Wi-Fi连接。即便它们当中只有一个使用“b”类设备，都会使整个网络速度下降至“b”。（这并不影响电脑的有线连接。）
不过，如果你的无线路由器速度够快，而且你对它很满意，你可以与Fios服务一起保留下来。我就是这么做的，因为我正在使用Belkin 'Pre-N'路由器，它的速度和覆盖范围比我见过的任何“g”类路由器都要好。我采用了Verizon简单的老式有线路由器，在上面插入了我的无线路由器。其他人则彻底放弃了Verizon的路由器，乾脆把Fios电线直接插入他们的无线路由器。这样做唯一的缺憾就是，Verizon称它安装的路由器包括能够诊断Fios问题的特殊软件。
问：我可以在iMac电脑上使用Firefox浏览器吗？我的操作系统是9.1版本。
答：不幸的是，不可以。虽然Firefox可以在Mac上运行，但它只支持苹果于2001年推出的操作系统Mac OS X。Firefox在Mac上运行的最低系统要求是Mac OS X 10.1。你电脑上的操作系统完全不同，比较陈旧，而且功能要少得多，苹果电脑实际上差不多已经放弃它了。顺便说一下，对于Windows用户，Firefox需要Windows 98或者更高版本，对于这两个平台，也都有最低的硬件配置要求。Firefox还可以在Linux操作系统上运行，这个平台上也有最低配置要求。所有上述平台的最低要求可参见
www.mozilla.org/products/firefox/system-requirements。
