Installation Problem

Posted on 1999-07-13
Medium Priority
Last Modified: 2013-12-16
Why Does the Computer That I am Installing Windows 95 on
Constantly give the ERROR:"Invalid System Disk" Replace an
hit any key. After a successful Instalation
The Machine is a 486sx with  20mb memory, a 6.8 gig maxtor hard drive,
and the only loaded software is DOS 6.20 with the UpGrade to
Dos 6.22. And the Samsung CD-ROM Driver Software.
The windows 95 software ins being installed from the Original CD-Rom
Question by:timberwolf1
  • 5
  • 4
  • 4
  • +8

Author Comment

ID: 1747183
Edited text of question.

Expert Comment

ID: 1747184

Check your CMOS Setup, it might be changed to NONE. Set it to AUTO to recognized your hard disk. This changes occurs because of your low battery performance. Since you have 486, Im pretty sure, your PC battery is getting low energy.


Expert Comment

ID: 1747185
Since You're using an older computer, are You using any kind of drive overlay software?
Which version Win95 is it?
When You boot from a diskette and change to c: what is the result, if You get to the c: prompt what does a dir show?
If this doesn't work type the following an post the textfile
fdisk/status>test.txt <enter>

When You're not using drive overlay software, how does the system react to:
1 fdisk/mbr (do it with the fdisk program of windows)
2 sys c: (also done with win95 startup disk)
You only have to try this when there is a c: prompt reacheable.


The 14th Annual Expert Award Winners

The results are in! Meet the top members of our 2017 Expert Awards. Congratulations to all who qualified!


Expert Comment

ID: 1747186
Just checking but, you didn't leave a floppy disk in the floppy drive did you?


Expert Comment

ID: 1747187
Ensure that the bootable diskette is able to boot to the CD ROM Drive, to read the CD.    

Expert Comment

ID: 1747188
Can your BIOS support the 6.8G HD?

Author Comment

ID: 1747189
Thanks for all the Ideas Have tried them All with the result that
none worked.

 Made a System disk on a Identical machine in windows 95 format.
 After booting just fine on the machine I was trying to Install Win95 on
 Came up with a a: prompt, type the command Format c:/s

 It read the hard drive for a few seconds and displayed the following
Drive C: non-removable media
all files will be lost procced with format y/n
after replying "Y" the machine displayed

A:\ "(without formating the C: Hard drive)"

Expert Comment

ID: 1747190
Run Fdisk and select option Number 4. Does it show any partions?

Author Comment

ID: 1747191
To Cumbo

 The Maxtor Disk That was used with the drive Installs EZ-Drive on the
 physical disk that enables the bios to access the larger partition sizes.

 You may hit crtl <Key> to interupt the boot process.
at which time the machine displays

 hit "C" to continue boot or
 hit "A" to boot from floppy

Expert Comment

ID: 1747192
The EZ-Drive doesn't matter in this case. Fdisk will tell if the primary partition is active. Probably is if EZ-Drive was used to partition and Format the drive.

If DOS is only operating system installed, put in your DOS Setup disk and type SYS C: and press enter. the computer should respond with System Files Copied.

If this works reboot and see if the error message still comes up.


Expert Comment

ID: 1747193
I think jvsteen was on the right track with the FDISK /MBR but are you sure you used the WINDOWS Fdisk command?  If you just typed FDISK /MBR it may have used the DOS command depending on your PATH statement.
Just to be sure, try the following:

c:\windows\system\fdisk /mbr

reboot and see if it makes any difference.

BTW, are you installing Win95 A or B?


Expert Comment

ID: 1747194
What happened?


Expert Comment

ID: 1747195
Does it happen every time or every other time?  If it's every other time, it's prolly a hard drive going bad.

Expert Comment

ID: 1747196
Run EZ-Drive again and see if it gives a warning about exsisting files that will be lost. Normally, EZ-Drive will ask you to insert a disk containing your operating system.

After inserting this disk you should see the bar graphs as it copies the files.

This will allow a direct boot into the C: drive. The only files installed at this time are Command.com, IO.sys & Msdos.sys. The later two are hidden.

At this point you must either A. Create or copy a Config.sys & Autoexec.bat files onto the C drive or, B. Press the spacebar and boot from a Floppy containing the above files. These files must contain your CD Drivers + a Himem.sys statement.


Author Comment

ID: 1747197
to All Thanks loads for the Information
I am installing windows 95A this is the only copy I have and as I am a severly
disabled student (rhumatoid arthritis) "please dont ask me to purchase anything"

I used a Windows 95a System disk in the A drive, Booted from that just fine.
Fdisk on the win95 indicates all partions and drives just fine. However when
I inssue the format c:/s command the screen prompted as follows

Non-Removable Media Drive C:
All files will be lost
Proceed with Format (Y/N)
After responding with the "Y" key press
The Machine Blanks the screen for a few seconds and the displays the

It Dose not format the C:Hard drive at all
We have call tech support at Maxtor and they say the HD is Good!!!
I am about to try win 98 on the machine instead and see if that does any better


Expert Comment

ID: 1747198
FDISK/MBR must be run from a bootable floppy with the same OS as the HD.Running it from the HD will do nothing (which is not obvious,since it gives no feedback anyway).

Are you sure of your HD jumper settings?

Is the CD slaved to the HD? If so,see if you can format after removing the CD (and setting HD to 'Single').

Replace the HD data cable with the CD's,or if slaved,with the CD's connector.

Try manually setting the PIO mode to 0 in BIOS.

Expert Comment

ID: 1747199
Your IDE controller doesnt support that big a Harddisk !
If you buy a EIDE controller your problems is solved !
- I think !

Expert Comment

ID: 1747200
1. "Invalid System Disk" this case for not active the Hard Disk with fdisk.
2. Becasue your hard disk is 6.8G, it sometimes run on ATA-3 (UDMA3 Model 4)
    486 mainboard cannot support ATA-3.

Are you check the hard disk or your mainboard ?

Expert Comment

ID: 1747201
timberwolf1 - not sure if you know how this works:

If colinccm's answer fixed your problem,give him the points.If not,you should reject it.(He should have posted it as a comment first).

If one of the current comments solved it,invite that person to re-post it as an answer.

In any case,please let us know how you're doing.

Author Comment

ID: 1747202
Mother board and Cnotroler according to manufacturer's specs is capable of
running Indicated hard drive an Windows 95a , 95b, os2 Operating Systems
and Below The Ata-3 problem According to the Tech we talked to Should not be
the Culprit. MB has been shipped to factory for evaluation.

 I appreciate the Information and It has helped me Diagnose whats not Wrong with
 my fathers System. However, Nothing yet has gotten the thing to accept the
 win 95a OS including The schematic of the mother board I obtained indicating the
 correct jumper settings for a various number of os conditions. Sorry fellas nothings worked Yet. Will keep you updated as to Progress of condition

Expert Comment

ID: 1747203
check it again.

Does your CMOS was set to LBA or NORMAL?

Accepted Solution

knowme earned 200 total points
ID: 1747204
Error Message "Invalid System Disk" After Setup Reboots

The information in this article applies to:

Microsoft Windows 95
Microsoft Windows 98

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.

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.

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:

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:

      attrib c:\msdos.sys -s -h -r
      copy c:\msdos.sys c:\msdos.xxx
      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:

TITLE : Windows 95 Setup: Description and Troubleshooting Steps

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.

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

TITLE : Methods to Detect a Boot-Sector Virus


Featured Post

Learn to develop an Android App

Want to increase your earning potential in 2018? Pad your resume with app building experience. Learn how with this hands-on course.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This is an update to some code that someone else posted on Experts Exchange. It is an alternate approach, I think a little easier to use, & makes sure that things like the Task Bar will update.
This article provides a step by step guide (with screenshots) showing how to create a new local (test) Administrator user profile in Windows 10 for troubleshooting purposes, and then how to remove it.
With the advent of Windows 10, Microsoft is pushing a Get Windows 10 icon into the notification area (system tray) of qualifying computers. There are many reasons for wanting to remove this icon. This two-part Experts Exchange video Micro Tutorial s…
In this video, viewers will be given step by step instructions on adjusting mouse, pointer and cursor visibility in Microsoft Windows 10. The video seeks to educate those who are struggling with the new Windows 10 Graphical User Interface. Change Cu…
Suggested Courses

599 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question