Operating Systems Domains
OS Diagnosing & Troubleshooting part 2
3.2 Recognize common problems and determine how to resolve them.
Troubleshooting Windows-specific printing problems
Print spool is stalled This can be solved by clicking on the File menu from the Printer Properties and selecting Restart Printing.
Incorrect/incompatible driver for printer First make sure that this is the proper driver for the printer if it is, try removing then reinstalling the driver.
Try using the Generic/Text Only printer driver for your printer. This can help determine whether or not your printing problem is related to your printer driver. If the Generic driver works try getting a new driver from the manufacturers web site.
Use Device Manager to Verify Port Settings Use Device Manager to verify that your printer port settings are correct and that no resource conflicts exist.
General Protection Faults
General protection faults (GPIs) are caused when a program tries to access a portion of memory that is has not been allocated by Windows or is already being used by another program or TSR. When this happens the screen turns blue with the GPF error message.
Run scandisk / defrag
Remove any TSRs or programs which were running before the GPF.
Remove and reinstall the program that caused the GPF.
Disable power management and screen savers
If you frequently receive GPF errors from different programs you may have to reinstall windows
This program has performed an illegal operation or This program has produced a General Protection Fault . Both of these messages refer to the same type of error. Windows has attempted to write information to a space in its memory that is already in use by the program. Reboot the computer, if problem persists run scandisk.
Invalid working directory
Ensure that the path in Working Directory is correct, or make sure the CD is in the drive and that the drive is mapped, windows loaded without logging you into the network and mapping the appropriate drive letter specified in the application shortcut properties.
System lock up
Problems with applications or hardware can lock up a system for many reasons. When the system locks up reboot the computer this usually corrects the problem. If lock ups occur with a certain application frequently try removing and reinstalling the application. In the event that your computer continually locks up with different applications, try running Scandisk and Defrag if this does not help it could be a hardware problem such as an overheated CPU.
Option (Sound card, modem, input device) or will not function
Check Device Manager to see if the device is listed and working properly if not reinstall drivers, if this does not work:
Check for conflicting IRQ's
Check that card is seated in the mother board properly
Application will not start or load
If an application does not start, you should first restart the system . If this does not solve the problem, try reinstalling the application. Some applications require certain DLL or runtime files which are not included with windows or they may be the wrong versions.
Cannot log on to network (option – NIC not functioning)
The most common network adapter problems are interrupt conflict and transceiver setting.
Things to Check:
Do the setting on the card match the setting in the network software you using
Is there a conflict between IRQ's
Is there an I/O address conflict
Is there a memory conflict
Is the cable attached securely
Is the adapter card set to the correct speed setting for the network
TSR (Terminate Stay Resident) programs and virus
These programs start when you first turn on your computer and stay in memory, ready for your use, even if they are not active on your screen. These programs can take system resources. These stay resident programs may include screen savers, anti-virus protection, and any DOS or Windows programs that were opened but never shut off.
Terminate and Stay Resident. "Memory Resident" viruses go into memory and stay there while the computer is still running. TSR viruses usually design a method by which they are put into memory when the computer is booted, and then run until the computer is shut down.
Applications don’t install
How Windows 9x Accommodates Application Problems
Some Windows-based and MS-DOS-based applications may not run well under Windows 9x because they were written to take advantage of characteristics of older operating systems. For example, certain applications use a portion of the title bar to include items other than the title, such as a Quick Help button. Because Windows 9x title bars are not formatted in the same way as Windows 3.x title bars, some information may be overwritten when you run these old applications.
In addition, some applications use interrupts that are not automatically supported by Windows 9x. Others do not handle long file names well, or they incorrectly check for the operating system’s version number.
Windows 9x provides the Make Compatible utility to make compatible an application that is initially incompatible with Windows 9x. You can use this utility to troubleshoot if you have trouble printing from an application, or if an application stalls or has other performance problems. This utility provides the means to increase stack memory to an application, emulate earlier versions of Windows, and solve other common problems that cause an application not to run with Windows 9x. Click the Start button, click Run, and then type mkcompat.exe.
Running Terminate-and-Stay-Resident Programs
Some older terminate-and-stay-resident programs (TSRs) rely on MS-DOS interrupts to monitor everything that happens on the system. However, because of its protected-mode file system, Windows 98 does not use MS-DOS interrupts. If Windows 9x detects that a TSR is trying to monitor these interrupts, it will accommodate the application and send all system information through MS-DOS interrupts. In this way, the TSR can monitor system events successfully. However, doing this will significantly slow the performance of the operating system.
Fixing Version-Checking Errors
Some applications incorrectly check the version number of Windows 9x. Incorrect version-checking techniques sometimes invert the two bytes that record the version number; thus, version 3.10 would be reported as 10.3. Windows 9x tries to accommodate this possible version-checking error by reporting 3.98 as the version. In this way, if an application looks for a version greater than 3.10 or its inverse, 10.3, the new Windows 98 version proves to be greater.
If the application looks for an exact match for the version number, such as Windows version 3.10, it may not run under Windows 9x. To resolve this problem, add the following line to the [Compatibility] section of Win.ini:
To determine the compiled module name, right-click an executable file in Windows Explorer, and then click QuickView. The Module Name line provides this information. After you have obtained the module name, the section you add to Win.ini should look similar to the following entry for cc:Mail:
Running Applications That Replace System Dynamic-Link Libraries
Some setup applications do not check the version of the system files they are installing and overwrite the newer Windows 98 versions of those dynamic-link libraries (DLLs). Windows 98 restores its original DLLs after every setup application runs and for the first three startups thereafter. If an application stops running or behaves erratically after you install it, you may need to obtain an updated version of the application that does not overwrite Windows 98 system files.
If your application must run with a replacement file, you can add that file to the \Windows\System\Vmm32 directory (which is initially empty after you set up Windows 98).
Windows 2000 Windows Installer
Windows Installer is a component of the Windows 2000 operating system that simplifies the application installation process.
With Windows Installer and the .msi package file format, software installation and removal has become more reliable and resilient while providing a larger set of installation options. Windows Installer performs the following tasks:
Restores original computer state upon installation failure: Windows Installer keeps track of all changes made to the system during the application installation process. If the installation fails, Windows Installer can restore, or roll back, the system to its initial state.
Helps prevent certain forms of inter-application conflicts: Windows Installer enforces installation rules that help to prevent conflicts with shared resources between existing applications. Such conflicts can be caused when an install operation makes updates to a dynamic link library (.dll) shared by an existing application, or when an operation deletes a dynamic link library shared by another application.
Reliably removes existing programs: Windows Installer can reliably uninstall any program it previously installed. It removes all the associated registry entries and application files, except for those shared by other installed software. You can uninstall an application at any time after a successful installation. (Removal should not be confused with rollback, which restores a computer to its initial state when an installation failure has occurred.)
Diagnoses and repairs corrupted applications: An application can query Windows Installer to determine whether an installed application has missing or corrupted files. If any are detected, Windows Installer repairs the application by recopying only those files found to be missing or corrupted.
Is the correct user name and password being used
Are the proper protocols installed
Are network cables loose, damaged, connected or to long
Is the network adapter card working properly (see above)
Viruses and virus types
What they are
A computer virus is a program designed to spread itself by first infecting executable files or the system areas of hard and floppy disks and then making copies of itself.
Types of Viruses
Boot Sector Stays resident by infecting the boot sector of the computer. Each time the system is booted, it is re-infected from its own boot sector. Any time a floppy disk is inserted into the drive, the floppy’s boot sector is infected. If a machine is booted from or even if an infected floppy disk is left in the floppy drive when the system is rebooted, that computer will then be infected.
FAT Virus infects the File Allocation Table of a hard drive, these usually cause a loss of files that are on a hard drive.
Memory viruses are viruses that execute and stay resident in memory.
Macro viruses are viruses that attach themselves to documents in the form of macros. Usually in Microsoft Word and Microsoft Excel documents
CMOS viruses are viruses that make themselves resident in the CMOS . These viruses can damage the hardware of the computer.
Benign virus might do nothing more than display a message.
Malignant virus cause damage to a computer system, such as corrupting files or destroying data.
In the Wild virus A virus that has been found in more than one organization or company.
Worms instead of spreading from file to file, they spread from computer to computer, infecting an entire system. After the initial infection, the worm attempts to spread to other machines on a network.
Trojan Horse designed to cause damage or do something malicious to a system, but are disguised as something useful. Unlike viruses, these don't make copies of themselves.
Sources (floppy, emails, etc.)
Virus code must be executed to have any effect, files that are pure data, such as graphics, sound, and plain text files are usually safe. The virus code has to be in a form, such as an .exe, .com, bat or a Word .doc file, that the computer will try to execute.
If your computer is infected with a boot sector virus, the virus tries to write copies of itself to the system areas of floppy disks and hard disks. Then the infected floppy disks may infect other computers that boot from them, and the virus copy on the hard disk will try to infect still more floppies.
You can't get a virus by reading a plain-text E-mail message, it is only when you open an attachment containing an executable program.
How to determine presence
In most cases, it is difficult to detect a virus, erratic system behavior, frequent lock ups, system won't boot all these could be caused by a virus. The only way to know for sure if a virus present is to use Antivirus software
Antivirus applications have the ability to remove most viruses, but there will be some which can not be removed. For those that can not, you will have to boot the system with a start disk then use FDISK with the /mbr option ( to over write the boot sector) and FORMAT the drive.