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April 1996 Features

Prevent a Titanic Disaster

When you get that sinking feeling, throw your PC a lifeline!

By Karen Kenworthy, Contributing Editor

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Add/Remove Program Properties

One minute, you and your PC are sailing toward the horizon, hard disk humming. Then, without warning, you feel the ship lurch. In the blink of a text insertion point, you know you're on the verge of disaster.

Sooner or later, computer tragedy strikes every system. A hard disk's life ends suddenly, a ravenous program eats some vital bit of data, or a rogue operating system sinks your well-engineered ship-mishaps like these are bound to ruin your day, and maybe even your week.

Careful planning can cut your downtime to a minimum. Even if you're not a master mechanic, it's possible to get your machine sailing once again.

It's the little things

Sometimes an easy-to-fix problem, like a loose cable or tiny flaw in a disk's surface, causes big-time headaches such as data loss, system crashes or operating errors. So it's a good idea to perform a few simple checks and adjustments before attempting any major overhaul. With a little luck, one of these tricks will get your system going again:

If your system's performance is odd or slow, scan your entire hard disk and RAM for viruses. Though they are rare, viruses can cause a variety of problems. Symantec and others sell commercial programs that can detect and remove almost all viruses in Windows 95. You can also download McAfee's popular shareware scanner from several locations, including CompuServe (GO: MCAFEE), AOL (Keyword: McAfee), and the McAfee ftp and Web sites ( and

Ask ScanDisk to test your hard disk. Be sure to specify a thorough test so any bad disk sectors will be detected, along with the usual check for directory and file system corruption. You'll find ScanDisk under Start/Programs/System Tools in Windows 95.

Turn off your computer for 30 minutes, then turn it on again. If your problem disappears, at least for a while, your PC may be overheating. Check for clogged or dead power-supply fans. Also check the fan attached to your CPU chip. If your CPU does not have its own fan, get one (for about $15) and install it.

Re-seat (unplug and reinsert) all adapter cards, data cables and power cables. This helps remove corrosion from contacts and ensures all connectors are firmly in place.

Undo any recent system changes. This includes the installation of new drivers, application software and hardware, plus any changes made to settings via the Control Panel. In Win95, you can uninstall Win95-compatible programs with the Add/Remove Programs applet in the Control Panel-a far cry from Windows 3.1x's hunt-and-pray procedure.

Restore from a recent backup-but be sure your backup and restoration procedures are Windows 95-compatible. Otherwise, you may make matters worse by corrupting the Registry or destroying long filenames. Windows 95 comes complete with a backup utility. The one negative to backing up from Win95 is that you can't back up the Registry.

Reinstall application software or Windows 95. If your problem persists, it's not a minor mishap any longer. Time to take more drastic measures.

Registry remedies

SYSTEM.INI and WIN.INI contain lots of vital information about your hardware and software configurations in Windows 3.1x. In addition, most Windows applications have .INI files all their own, for details specific to the program.

Under Windows 95, however, most of this data has migrated to an elaborate database known as the Registry, where information is stored in two disk files: SYSTEM.DAT and USER.DAT. SYSTEM.DAT contains various software and device information essential to the proper operation of Windows 95 and your applications. In it, you'll find most of the settings you've made via Control Panel, and most of the hardware information that appears in the Device Manager display. SYSTEM.DAT is stored in the WINDOWS directory of your boot drive.

The USER.DAT file contains information related to the individual users of your PC. Within the file, you'll find entries recording the user's choice of screenery: wallpaper, colors, fonts and more.

By default, there's only one USER.DAT file on your computer's hard disk, but if you've enabled User Profiles, you'll find a USER.DAT file in each user's PROFILES directory.

Corrupt or missing Registry information can cause your computer to hang or crash; it can also disable certain program features or even prevent your computer from booting. Fortunately, the designers of Windows 95 knew how dependent we'd all become on this database. That's why they provided several ways to restore the Registry should something go wrong.

Restoring the Registry

Every time Win95 starts successfully, it automatically copies the current Registry files. These copies are named SYSTEM.DA0 and USER.DA0, and can be found in the same directories as SYSTEM.DAT and USER.DAT. When Registry corruption keeps Windows from booting, you can replace the corrupted files with these emergency backups. Here's how.

Boot your computer to a Safe Mode Command Prompt by pressing F8 and then selecting Safe Mode Command Prompt Only from the pop-up menu. Windows 95's Safe Mode is designed to get the OS up and running with a bare-bones configuration when something has gone wrong with the system's settings. The graphics drivers are minimal (640x480 pixels, 16 colors) and the system's performance will be nowhere near as fast as normal, but Safe Mode makes it possible to troubleshoot malfunctioning drivers or program settings. There's also a version of Safe Mode that loads network drivers for those who need access to remote systems while troubleshooting. Safe Mode Command Prompt Only will bypass all startup files and put you right into DOS mode.

All Registry files are protected by having their System, Hidden and Read-Only file attributes set. Before one of these files can be replaced, these attributes must be removed. To do this, enter the following DOS commands:


If you installed Windows to a different directory than the default, be sure to use the proper locations and names of your Registry files. If your computer has more than one user, be sure to reset the attributes of each user's USER.DAT and USER.DA0 files. These files can be copied just like normal files. Here are the DOS commands to do the job:


Once all copies have been made, restore the Registry files' original attributes with these DOS commands:


Again, be sure to insert the proper locations and names of your Registry files, and if your computer has more than one user, be sure to restore the attributes of each user's files, then restart Windows 95 normally (Ctrl+Alt+Del).

System.1ST-and foremost

Want more? Windows 95 also provides a special version of SYSTEM.DAT for extreme emergencies. This file is named SYSTEM.1ST and is located in the WINDOWS directory of your boot drive. It's an exact copy of the SYSTEM.DAT file created by Setup the last time you installed Win95. It contains information about your original hardware configuration, and little more.

SYSTEM.1ST will allow you to start Windows 95, but it's missing a lot of data. Once Windows is running again, you may need to reinstall your Win95 applications and redo any configuration changes and driver updates you've made since your first install.

Is ERU good for you?

It's a good idea to make backup copies of the Registry files. This can be especially handy if you're about to make changes to your Windows configuration and would like the ability to quickly revert to the original setup should something go wrong. Boot your computer to a Safe Mode Command Prompt, remove the SYSTEM.DAT and USER.DAT files' System, Hidden and Read-Only attributes, then copy the files to a diskette or a directory on your hard drive or network.

Or, if you prefer, you can use Microsoft's Emergency Recovery Utility (ERU) to create an Emergency Recovery Diskette (ERD), a special, bootable floppy containing backup copies of key Windows files, including MSDOS.SYS, COMMAND.COM, IO.SYS, SYSTEM.DAT, PROTOCOL.INI, WIN.INI, AUTOEXEC.BAT, SYSTEM. INI and CONFIG.SYS. When you boot your computer from this diskette, the backup copies of these files are automatically copied over the versions found on your hard drive. After the files have been copied, remove the diskette and reboot. The repair is now complete.

This utility is a nice idea-in theory. Unfortunately, in practice ERU has a few problems. Its biggest drawback is that it's limited to a single diskette. If your configuration files won't all fit on a single floppy, ERU silently omits some files from the list of those being preserved. Most often, it skips the SYSTEM.DAT file, since all by itself it's usually too large to fit on a diskette. ERU also doesn't know about User Profiles. As a result, it only attempts to back up the USER.DAT file found in your WINDOWS directory, and not the individual USER.DAT files.

Unless you notice the omissions, you may be in for a big disappointment when it comes time to restore files from the ERD. But if your configuration files are small, ERU can provide a convenient way to back up and restore several important files at once. If you'd like to give it a try, you'll find ERU.EXE and its associated files in the \OTHER\MISC\ERU directory of your Windows 95 CD-ROM, or you can download a copy from several online sources, including Microsoft's Windows Web site ( and the WINDOWS Magazine forums on CompuServe and AOL. See WINDOWS Magazine Online Locations

Rebuilding your hard disk

Sometimes, replacing a few files isn't enough. If your hard disk has been badly corrupted you may have to rebuild it.

If a command-line Windows 95 restore program existed, rebuilding a hard disk would be easy. You'd just boot your computer using a startup disk, run your restore program from a diskette, then restore all your Windows 95 system files, applications and data.

Unfortunately, as of this writing no such program exists. All current Windows 95 restore programs can only run once Win95 has been loaded. That's because long filenames are not supported by the subset of Windows 95 that loads when you boot to a DOS prompt. This creates a chicken-and-egg problem: How do you restore a backup of Windows 95 if Win95 must already be on your hard disk to do so?

This riddle has an answer: The chicken must come first. In other words, you must install Win95 from your original diskettes or CD-ROM, then restore your other files from your backup. To make matters worse, most of us have the Upgrade version of Win95, which won't install unless your hard disk contains a copy of DOS, so you must install DOS as well.

To perform this mournful task, you'll need your original Windows 95 diskettes or CD-ROM, a DOS boot diskette and, most importantly, a recent backup of your hard disk made by a Windows 95-compatible backup program. If you're not using the backup and restore programs that come with Win95, you'll need your backup and restore program's diskettes, too.

We'll assume the hard disk being rebuilt has been formatted. Got everything on our list? OK, let's go:

Insert your boot disk, then power up your PC.
Use the SYS utility to transfer the operating system files from your diskette to your hard disk. The command to enter is SYS C:, assuming C: is your boot drive.
Copy your drivers from the boot diskette to your hard disk.
Run EDIT.COM from your diskette and create a CONFIG.SYS file on your hard disk that loads the drivers you just copied.
Remove your boot diskette, then press Ctrl+Alt+Delete to reboot your computer.
Insert your Windows 95 Disk 1 or CD-ROM and run SETUP.EXE. If you're using a third-party backup and restore program, reinstall that software.

Restore your most recent backup. Hard disk crashes, lost files and system hang-ups may be disasters, but they're not incurable. Armed with these tips for troubleshooting pitfalls, you'll have your PC afloat faster than you can say, "Reboot!"

Karen Kenworthy is the author of Visual Basic for Applications, Revealed! (Prima Publishing, 1994). She is also a contributing editor at WINDOWS Magazine and the manager of WINDOWS' forums on America Online and CompuServe. To find her E-Mail ID Click Here

Hard Drives Made Easy

By Karen Kenworthy

Installing a new hard drive can be challenging, but it's not as difficult as you might imagine. If the new drive is an IDE drive, set its jumpers as follows.

If this drive will be the only one in your computer, use the "Only Drive" configuration in the manual. If the new drive will have a partner, configure one drive as a "master" drive and the other as a "Slave."

If the new drive is a SCSI drive, assign it an unused SCSI ID using the drive's ID switch or jumpers. Lower ID numbers are recognized first upon bootup, so set your drive as close to the beginning of the SCSI chain as possible.

To replace an old drive, take out the screws holding the drive in place, detach all cables and then remove the drive. Slide the new drive into the empty drive bay, and lock it in place with screws. Some bays require you to attach rails to the side of the drive before insertion. Your computer should have come with spare rails. If not, you can pilfer rails from an old drive or purchase new ones.

Attach one of your power supply's spare power cables to the new drive. Locate the appropriate data cable (connected to either your IDE or SCSI controller) and hook one of the cable's unused connectors into the drive's data socket. Any unused connector will do.

Insert your startup disk and power up your computer. Run your computer's CMOS Setup program. If your CMOS has a hard drive auto-detect option, choose that. Otherwise, manually change your CMOS settings to reflect your new hard drive configuration. (Note: This only applies to IDE drives.) Save your CMOS settings and reboot your computer-but don't remove the startup disk until you finish all of the following instructions.

Run FDISK to format the disk, select the appropriate drive and create at least one drive partition. If the new hard drive will be your boot drive, create a primary partition. Create an extended partition on non-boot drives or other partitions. Exit FDISK and reboot your computer.

Run FDISK again, select the drive number of your boot drive and ask it to mark the primary partition "Active." This is how your BIOS knows which partition to use when booting. Exit FDISK and reboot your computer once more.

Run FORMAT to initialize your new drive's partitions. If formatting your boot partition, use the command FORMAT /S drive letter:. Otherwise, use the command FORMAT drive letter:.

Your new drive, and its shiny new volumes, are now ready to use. You can take out the startup disk, install Windows 95 or another operating system if this is a boot drive, then reboot your computer and start filling up all that new space!

If You Start Me Up

By Karen Kenworthy

In addition to these files, you should add any hardware drivers your system needs for the hard disk, CD-ROM drive or SCSI adapter. Create a CONFIG.SYS file on the startup disk to load these drivers if necessary.

A startup disk is a bootable diskette-one that contains enough of Windows 95 to start your computer, display a command prompt and repair your hard disk.

You can build your own startup disk by manually copying your favorite utilities, or you can let Windows do the job. If you didn't set up a diskette upon installation, if you've since changed disk compression settings or if you've misplaced the original startup disk, Control Panel can make a new one for you. Just double-click on Control Panel's Add/Remove Programs icon, then select the Startup Disk tab. Click on the Create Disk button and follow the directions that appear on screen.

The startup disk that Windows 95 creates for you will contain the following:

DRVSPACE.BIN Allows your computer to read and write compressed drives.
COMMAND.COM Displays your computer's command prompt.
FORMAT.COM Performs high-level formats of disk partitions and volumes.
SYS.COM Transfers the startup disk's files to a new drive.
FDISK.EXE Partitions a hard disk.
ATTRIB.EXE Modifies a file's System, Hidden, Read-Only and Archive attributes.
EDIT.COM A simple text file editor.
REGEDIT.EXE Allows you to make changes to the Windows 95 Registry.
SCANDISK.EXE Checks your disk for surface flaws or corruption of its data.
DEBUG.EXE Can be used by programmers to create very small utilities, search and edit the contents of RAM or perform very low-level disk I/O.
CHKDSK.EXE Checks your disk's directories and file system.
UNINSTAL.EXE Uninstalls Windows 95. Note: Uninstall is supported only if you installed Windows 95 in your original WINDOWS directory, you requested Setup to save your original system files, and you have not compressed your hard disk or changed your disk configuration since Windows 95 was installed.

Regiment the Registry

By Serdar Yegulalp

DOS and 16-bit Windows dealt with far less elaborate configurations than either Windows 95 or NT, so they didn't need a sophisticated means of storing system settings. The familiar .SYS, .BAT and .INI files are simply text files, with very little in the way of organization.

Windows 95 and NT, on the other hand, require a better way to store the wealth of system settings and driver information. The solution: Both OSes use the Registry, a database of system settings and names of needed drivers. The Registry is organized into sections and subsections similar to an outline.

For instance, one of the topmost levels (called a key) in the Registry is HKEY_CURRENT_USER. All the settings that pertain to the user currently logged in are stored here. Under HKEY_CURRENT_USER, you'll find other, less cryptically named keys such as Keyboard Layout, Software and Control Panel. Each of these contains further subdivisions.

HKEY_CLASSES_ROOT contains all the recognized filename extensions in the system. HKEY_LOCAL_MACHINE is a list of current hardware settings. HKEY_USERS is the archive of all users' options. HKEY_DYN_DATA stores all the hardware detection information and other low-level settings; if ever there were a key that should not be touched, this is it.

Registry keys can hold other data or keys that are attached to specific settings or programs. The key HKEY_CURRENT_ USER\Control Panel\Accessibility\HighContrast, for example, contains a list of settings for the high-contrast display scheme for visually impaired users. One of the entries in this section is HotKeyActive, with a value of 1-meaning that the hotkeys that toggle high contrast are enabled. To turn off that feature, replace the 1 with 0.

If you're curious-but cautious-type REGEDIT at the command line, and you'll be presented with the utility that lets you browse and edit the Registry. It's possible to make very powerful global changes by editing the Registry, but it's also possible to trash your system settings and render your copy of Windows 95 useless. Unless you know precisely what you're doing, don't change anything in the Registry.
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