6个可下载的引导光盘拯救你的电脑

Way back in the 20th century, Windows prepared you for the day your PC wouldn't boot. It came with a program that formatted a bootable floppy disk, complete with diagnostic and repair utilities. If you had the forethought to create that floppy while Windows was still working, you were ready when it eventually failed.

Alas, the Windows Boot Floppy went the way of DOS (the operating system it actually booted). Modern versions can't make that floppy (they can format a bootable DOS floppy -- if you have the drive -- but without utilities), and DOS can't handle NTFS hard-drive partitions.

Since Microsoft doesn't supply you with the ability to create an emergency boot disk, others have stepped in to fill the vacuum. Here are six worthwhile emergency boot CDs, all downloadable, and most of them free.

Yes, I know you can't download a CD. Most of these packages come as .iso files -- easily burnable disc images. If you double-click an .iso file, there's a good chance that a program you already own -- perhaps Nero Burning or Easy Media Creator -- will come up and burn it to CD. If that doesn't happen, download and install ISO Recorder.

Know your rescue OSes

Since DOS doesn't handle XP or Vista repairs well, each of these discs boots into one of the following three operating systems. It's good to know a little about them.

Windows PE: The official, CD-bootable version of Windows (the PE stands for Preinstallation Environment) makes the obvious choice for this sort of thing. Unfortunately, Microsoft maintains strict control, and few utility authors have received permission to use it.

BartPE: Since Microsoft won't share its preinstallation environment, Bart Lagerweij created his own, and he gives it away for free. But to avoid copyright infringement, he can't give you everything you need to create a BartPE disc. The missing elements consist of Windows XP installation files you may or may not already have.

Linux Live CD: The name refers to any version of Linux you can download as an .iso file and boot off a CD. But Linux can be an intimidating environment for the uninitiated, it doesn't always handle NTFS well (many versions can read NTFS but not write to it), and it is seldom geared to help with Windows problems.

Bring on the rescue discs

So let's get on with it. I'll start with discs that simply give you access to the files on your hard drive, and work my way up to the powerhouses that can diagnose and repair most boot problems.

Puppy Linux

If Windows won't boot, nothing gets you into your hard drive faster or more easily than Puppy Linux. Puppy isn't the most powerful version of Linux by a long shot, but it's great for accessing NTFS-formatted hard drives -- especially if you're not comfortable with Linux's whole mount concept. Just open the Drives window and select a drive, and Puppy will mount it for you -- in read/write mode, if possible.

If Puppy succeeds in mounting the drive with read/write permissions, you not only can copy your files elsewhere, but you can also edit them. Puppy Linux comes with AbiWord, which supports .doc files, and Gnumeric, which supports .xls. And even if it mounts read-only, you can still copy the files to an external drive, most of which are formatted in the universally accessible FAT32 file system.

But be careful how you click. Actions that take double-clicks in Windows, such as opening a file, take only one in Puppy.

Price: Free
Download Puppy Linux.

BartPE

The BartPE operating system makes a pretty good boot disc on its own, getting you into Windows and letting you access your drive. It doesn't have much in the way of repair utilities, but it has chkdsk, which should probably be the first one you try. And it can run any portable Windows utility (that doesn't require an installation) you care to give it.

Creating a BartPE disc isn't as easy as double-clicking an .iso file. You have to download, install, and run Bart's PE Builder. To create a CD, the program needs the Windows 2000 or XP installation files. One place you're sure to find them is an actual Windows installation CD-ROM. But the recovery disc that came with your PC probably doesn't have them.

Luckily, if your PC came with XP installed (and thus, not with a true XP CD), the necessary files are probably in a folder called C:\Windows\i386. But I do mean probably, not definitely. However, since the PE Builder is free, you're not losing much if it can't create a disc.

Although BartPE's program selection is slim, the PE Builder lets you add other programs to the disc before you burn it.

Price: Free
Download BartPE.

Vista Recovery Disc

It looked like Microsoft was finally going to do the right thing. Beta versions of Vista SP1 came with a modern equivalent of the old Windows Boot Floppy -- a Start menu option called "Create a Recovery Disc" that burned a Windows PE-based emergency CD.

Alas, Microsoft removed that feature before SP1 shipped -- but not, fortunately, before NeoSmart turned the disc into an .iso file and made it available on their site.

Running on the Vista version of Windows PE, the Recovery Disc is basically a Vista installation disc minus the install files. It even has an "Install now" button that asks for a Product Key before failing. You're better off clicking the "Repair your computer" button.

Among its Vista-only options are a tool for diagnosing and fixing startup problems, a version of System Restore that uses restore points on the hard drive, the restore portions of Vista's backup program, and a memory diagnostic tool.

Price: Free
Download Vista Recovery Disc.

Ultimate Boot CD for Windows

This BartPE-based boot disc comes with a huge selection of tools to access your data and get your PC booting properly again. Some of them are even useful.

UBCD takes a long time to load and asks you some odd questions before it's finally up. But once it's there, you can edit the Windows Registry (yes, the one on the hard drive) in RegEdit, recover deleted files, and even run benchmarks. There are several malware scanners, four defraggers, and eight diagnostic programs (including HD Tune and Windows' own chkdsk).

This boot CD also includes backup utilities to help you salvage your files. There's a driver backup and a system profile backup whose Web-based documentation no longer comes up. And four separate image backup programs. One of those programs, DriveImage XML, I considered recommending in past articles but didn't because restoring from it requires a second Windows installation -- something the program gets with UBCD.

The experience of setting up UBCD is identical to creating a BartPE disc -- with the same possibility of failure. But when it works, you get a lot more.

Price: Free
Download Ultimate Boot CD for Windows.

Trinity Rescue Kit

This is the only Linux Live CD variant I've ever encountered that is intended specifically for rescuing Windows computers. As such, it's no surprise that it's a powerful and versatile repair environment.

But it's really not designed for Windows users. TRK's command line interface could humble anyone but the most devoted Linux geek.

If you take the time to read the 46-page documentation and learn the program, you'll be rewarded next time disaster strikes. Among the tools that will be at your disposal are a script that runs four different malware scanners, a tool for resetting passwords, a Registry editor, a program that clones an NTFS partition to another PC over a network, a mass undeleter that tries to recover every deleted file on the drive, several tools for recovering data off a formatted or dying disk, two tools for fixing master boot record repair programs, and hardware diagnostics.

Price: Free
Download Trinity Rescue Kit.

Active@ Boot Disk

Finally, we come to a boot disc that offers useful tools, is easy to use, and can be created from virtually any XP or Vista computer. The catch? At $80 (U.S.), it costs $80 more than the other five options put together.

Based on Windows PE, LSoft Technologies' Active@ Boot Disk offers a well-chosen collection of utilities, including image backup and recovery, a CD/DVD-based data backup program (Windows PE and Active@ load entirely into RAM, making the disc drive available for other uses), and a tool for recovering deleted partitions and files. You can change Windows passwords, wipe your hard drive, and choose between three partition managers. A Windows Explorer clone lets you copy files off of the hard drive.

You can even bring up Windows' Task Manager, although I'm not sure why you'd want to. And if you're feeling really geeky, there's even a HEX editor.

Price: $80 (10-day free trial period)
http://www.pcworld.com/downloads/file/fid,71019/description.html.