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Last reviewed: June 2004

SU0168: "Your Computer Already Has an Operating System..."

Upgrading Win98/SE/Me with a CD supplied by an OEM (sold with new computers) can fail but that can be overcome. The same may occur when trying to setup a Win9x dual-boot.

If you received a Warning SU0168 when attempting to upgrade or install another Windows, then its likely you're using an OEM version CD. You will be told "Your Computer Already Has an Operating System...", and the install aborts.

This page shows how to often overcome this problem and successfully upgrade Windows 9x with an OEM Windows installation CD.

THPC also uses this method to install a Windows to Dual-Boot Win9x + Win9x.


"Your Computer Already Has an Operating System..."

Retail versions of Win9x are always full versions and will install/upgrade wherever you want.

OEM CDs usually have words on the label similar to 'For Distribution Only with a New PC'. OEMs are Original Equipment Manufacturers like Gateway, Dell, and many others - they assemble/market new computers containing parts made by other manufacturers.

OEM upgrades are actually full version CDs. They're adjusted to artificially prevent them from upgrading an existing Windows 9x or perhaps installing another copy. This page shows how to use true MS-DOS to upgrade Win9x with a OEM CD.

Another reason for a failed installation is described in this Microsoft article:
Error Message: Your Computer Already Has an Operating System... [Q225252]
which refers to a dirty/damaged installation CD, or a corrupt Setupx.dll in Windows\System)

OSR2 Caution:

Please think carefully if you are upgrading from Windows 95 or 95A to Windows 95B (OSR2). The OSR2 never had an upgrade version and was designed to be sold only with new computers.

The Upgrade #1 fix below could work with OSR2 but it's quite risky! Try with OSR2 entirely at your own risk.

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Upgrade, or install, from an OEM Win9x installation CD

You can often fool the OEM installation CD into

(A) upgrading the current Windows 9x, or
(B) adding another full Windows 9x (a Dual-Boot, to a different logical drive).

The second usage (B, dual-boot) is not discussed here. It is successfully used with AddAWins.

Two methods of upgrading are discussed here.

Upgrade #1:
The first method has been used extensively and successfully by THPC. The two Windows files, & Winver.exe, are renamed from under true MS-DOS. Then the OEM Setup is run, again from under true MS-DOS. You MUST NOT try to install from outside true MS-DOS e.g. booting from a bootable Win9x OEM CD, and then installing, is likely to DAMAGE your current Windows. The install MUST be started from under true MS-DOS as described below.

Upgrade #2:
The second method is from a Microsoft page. Here the file, SetupX.dll, is extracted from the installation CD. This method is appropriate only in specific situations.

Read below for details on both methods of upgrading with an OEM installation CD.

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#1 Upgrading Windows 9x/Me when you get an Error Message SU0168.

Caution: It's possible some OEM upgrade versions may be specific to them. Using a different OEM version to upgrade a non-matching OEM Windows could possibly damage the existing Windows. That would force you to reinstall the current Windows with possible loss of data. It's a possibility, so please be aware of it! However, this method has never failed to work for THPC.

How to Upgrade Win9x using true MS-DOS if Error Message SU0168 occurs:
1. Note the name of the current Windows folder (usually C:\Windows).
  . Backup important data, passwords, settings, etc.
  . Boot with your Win9x boot disk and see if you can read files on a CD. If CD is not supported,
    copy the contents of the OEM CD to a new folder on hard disk (like D:\Win98).
2. Boot with Win9x boot disk inserted (leave it inserted until first reboot during OEM install).
  . At the A:\> prompt, type and press [Enter] after each line - be careful with spaces!
    where your current Win9x is installed in C:\Windows (alter if necessary).
3. Insert the new OEM CD, and type:   (but use Z:\WIN9X\SETUP /IS for a WinMe OEM CD)
    Z:\WIN98\SETUP /IS
    where Z: is the CD letter, or Z:\WIN98 is the location of CD files on hard disk.
    (note: there's a space between SETUP and /IS)
4. If OEM wants to install on C:\Windows.000, you change it to current Windows folder.
  . If the install fails to start, exit setup, and rename the two files back. You can now reboot
    back to the original Windows without loss.
NOTE: Do not be tempted to rename the Desktop folder or Desktop.ini, or do anything else when upgrading - you would risk the loss of many current Win9x items!

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#2 Upgrading Windows 9x/Me when you get an Error Message SU0168.

This second method, from Microsoft, has not been tested by THPC. Microsoft explains how to manage this in Setup.txt (on the CD). Microsoft says:
" Message SU0168
Your computer already has an operating system installed, which cannot be upgraded by this version of Setup. Please obtain the Windows 98 (or Windows Millennium) Upgrade."
This error can occur when you are attempting to install an OEM version of Windows 98 over a previous version of Windows.
An application has installed an OEM version of SetupX.dll that makes it appear that your current version of Windows is the OEM version.

If you suspect this, replace SetupX.dll with the correct version from your current install media.
1. Place the CD for your existing Windows 9x in your CD-ROM drive.
2. From a command prompt, change to the Win9(x) folder on your CD-ROM.
3. Type extract /A setupx.dll /L C:\
4. Copy the SetupX.dll from your C: to your Windows\System directory.
5. Run Windows Setup again. "

THPC Tip: Use Find if SetupX.dll is not located. Enter [CD]:\ in the Look in: box in Find. Enter Setupx.dll in the Containing text box, and click Find Now. Change the in the above (3) extraction line to the specific Cab (and be careful with spaces) e.g.
    extract setupx.dll /L C:\
THPC Tip: You may have to use true MS-DOS to copy the file from C: to _\Windows\System.
THPC Tip: ALWAYS backup a file BEFORE you alter/overwrite it.

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You may require permission from the OEM.

The following applies ONLY if you do NOT have a legitimately-owned OEM installation CD.

The information supplied on this page presumes you will approach the OEM for his permission to implement this fix. He will, quite correctly, expect you to ask him. He may even be unaware of this possible upgrade method. You can expect to lose any OEM support for your upgraded Windows.

Mostly, users will want to upgrade from Windows 95 (now extremely old) to Windows 98 (very old). Win95 is no longer supported by Microsoft. Win98 is probably not supported by now (Microsoft had declared withdrawal of support for Win98 some years ago but deferred that for a limited time).

The OEM will try to persuade you to upgrade to a new Windows XP system. That's to be expected. You will need to be persuasive!

Many OEMs will/should feel that such a 'minor' upgrade from one old Windows 9x to another old Windows 9x does not interfere with their overall business strategy and may, in fact, be in their interest in the long term. Do they still support Win98? Also there are other OEMs out there who would like your business when you do change to a new XP system!

It's a competitive commercial world but also a legal one, so it's hoped you will do the right thing when necessary.

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Please remember that you alone are responsible for the consequences of any changes you make to your computer hardware or software.

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