I formatted my hard drive.. Now what?

I just formatted my hard drive. Now when I start up the pc(formally windows98) I get an “Invalid system disk. Replace the disk, and then press any key” error. Is it looking for a startup disk? Can I create one on this pc? How?

Did you actually take a working computer system, running Win98, and re-format the system drive? Because if so, you have three options now:

  1. Boot off of an Emergency Recovery floppy you created earlier.

  2. Boot off of an install floppy for the new operating system of your choice, or

  3. Same as (2), but you may be able to boot off of a CD drive to install a new operating system - if your BIOS supports it.

Can you elaborate on how you got where you are right now?

Now, put your Linux CD in the CD-Rom, and reboot-- it will install the OS for you. Once that’s done, you can just boot up normally.

And if you’re reinstalling Windows, the same procedure applies.


You DID make a recovery floppy before you did this, right?


Assuming you have windows 98 go to Start>settings>control panel. Then double-click on the add/remove programs button, then click the startup disk tab. The disk you make will give you access to your cdrom drive in dos so you can install an operating system.

If you are using windows 95 or older, it will be more complicated to make a boot disk with cdrom support, but I’ll post instructions if you need them.

By formatting ie “format c:” without using the “format c: /s” (/s) switch which formats and installs the system files you now have a clean disk with no system boot files on the hard disk and it is asking for them. You will need to make or otherwise obtain a floppy with the necessary files and install them on your hard drive if your intent is to re-install 98. You will most likely also need to have the CD drivers installed as well if you need your system to “see” the CD drive for the OS installation files.

Format a floppy disk on another 98 system with the command

format a: /s

then copy the file sys.com from c:\windows\command directory onto the floppy.

Boot up your formatted system with this floppy and when the system is fully up type

sys c:

this will transfer the OS boot up files onto your hard drive and will allow your hard drive to boot. There are other drivers you will need to use as well if your intent is to use the CD drive per the example below.

You will need to have the following files on either a floppy or the hard disk if you intend to use the CD and install from the CD.

config.sys file (say on a floppy) needs the following lines and files on the floppy


autoexec.bat file (say on a floppy) needs the following lines and files on the floppy


The teac_cdi.sys and teac-cdi driver command can be replaced with whatever your applicable CD driver file is. In that this TEAC_CDI.sys driver will work with 95% + of IDE CD drives I can email you this driver if you wish.

astro if they have access to a computer running WIN98, then just make a boot disk. The drivers for cdrom will be on it.

Formatting a bootable disk under Win98 using explorer does not place any CD drivers on the disk. The “startup disk” procedure under the “Add/Remove Programs” icon under “Control Panel” will do this and I suspect this is what you are referring to. You are right that this is easier than hand rolling a boot disk and I should have suggested this as the best way to make a bootable disk with CD files.

The OP will still need to “sys c:” the c: drive from a boot floppy, however, if they want to transfer the OS to the the hard drive without re-formatting the drive with the /s switch.

Why not read the manual for the HD? Don’t have one? You can get instructions at the manf. web site.

As the person said, you cannot do anything at all without putting the system files on it & using Fdisk to make the HD active…