Error Message "Invalid System Disk" After Setup Reboots

ID: Q128730

The information in this article applies to:

Microsoft Windows 95
Microsoft Windows 98

SYMPTOMS

During the first reboot in Setup, you may receive the following error message:

Invalid system disk Replace the disk, and then press any key

You may also receive this error message when you boot from the startup disk.

Or, you may receive the following error message:

This version of Windows does not run on DOS 7.0 or earlier.

CAUSE

This error message may be caused by one of the following situations:

The system is infected with a boot-sector virus. This error is known to be caused by the AntiCMOS.A virus.

The system is running virus-protection software.

The system is using hard disk management software (such as Disk Manager, EZ-Drive, or DrivePro) for hard disk geometry translation. These tools provide support for hard disks with more than 1024 cylinders.

Setup was unable to copy the system files to the hard drive.

Security software has disabled access to drive C.

RESOLUTION

Use one of the following methods to correct the problem.

Systems Infected with a Virus

Use an anti-virus program to detect and remove the virus, and then reinstall Windows. Boot-sector viruses infect computer systems by copying code either to the boot sector on a floppy disk or the partition table on a hard disk. During startup, the virus is loaded into memory. Once in memory, the virus infects any non-infected disks accessed by the system.

Systems Running Virus-Protection Software

Boot the system using the startup disk created during Windows Setup. Use the SYS command from the startup disk to restore the system files to the hard disk.

Some computers use built-in anti-virus software that must be disabled in the computer's CMOS settings. For information about changing CMOS settings, consult the computer's documentation or manufacturer.

Systems Using Disk Management Software

Windows may not in some cases detect disk management software and may overwrite the master boot record (MBR) information. Refer to the documentation for the disk management software you are using for information about restoring the MBR.

Also, check the Setuplog.txt file for the following statement:

FSLog: BIOS Heads=:64:, BootPart Heads=:64:

The number above (64 in this example) may vary from computer to computer. If these two numbers are different, replace the system files on your hard disk according to the instructions in the "Reinstall the Windows system files" section below.

For additional information, please see the following article in the Microsoft Knowledge Base:

ARTICLE-ID: Q186057
TITLE : How to Tell If Drive Overlay Program Is Installed in Windows

Reinstall the Windows System Files

CAUTION: If you are using Disk Manager or any other disk drive overlay program on a hard disk, make sure that the overlay driver is loaded before you use the SYS command on that hard disk. If the overlay driver is not loaded and you use the SYS command on the hard disk, the drive may not be recognized as being partitioned by the disk drive overlay program and you could experience a data loss or inability to boot from the drive.

Although you can use the SYS command with Ontrack Disk Manager and later versions of MicroHouse EZ-Drive (or EZ-Max) after the overlay driver is loaded, earlier versions such as EZ-Drive 2.01s require that operating system files be copied to the overlay installation disk and installed by the overlay utility. In such cases the overlay may be damaged if you use the SYS command on the hard disk.

Boot the system using the Windows 95 or Windows 98 Startup disk.

At the MS-DOS command prompt, type the following lines:


      c:
      cd\windows\command
      attrib c:\msdos.sys -s -h -r
      copy c:\msdos.sys c:\msdos.xxx
      a:
      sys c:
      attrib c:\msdos.sys -s -h -r
      del c:\msdos.sys
      copy c:\msdos.xxx c:\msdos.sys
      attrib c:\msdos.sys +s +h +r

Remove the disk and reboot the computer.

Security Software Enabled

There is third-party software available that locks access to one or more hard disks. If this software is installed, contact the manufacturer about how to remove this software and safely restart Windows 98 Setup.

For more information about Windows Setup and troubleshooting steps, please see the following article in the Microsoft Knowledge Base:

ARTICLE-ID: Q129260
TITLE : Windows 95 Setup: Description and Troubleshooting Steps

MORE INFORMATION

The third-party products discussed in this article are manufactured by vendors independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability.

REFERENCES

For more information about boot-sector viruses, please see the following article in the Microsoft Knowledge Base:

ARTICLE-ID: Q82923
TITLE : Methods to Detect a Boot-Sector Virus

Additional query words: anti cmos


Keywords          : kberrmsg kbsetup win95 winboot win98 
Version           : 95
Platform          : WINDOWS 
Issue type        : kbprb

Last Reviewed: January 16, 1999