Bypassing BIOS Check when installing Windows 2000 on “D” Computers

Bypassing the Windows 2000 Installation Bios Check

More an more computers are arriving with recovery CD-ROM disks created by the computer manufacturer on which will be found the Windows 2000 installation files hidden deeply in their directories. The only problem is that in order to use those installation files, you must perform a full system recovery rather than merely loading the operating system alone. In addition, if you decide to change the motherboard, the recovery CD won’t work at all. Understand, we do not condone piracy in any form. We also do not condone the actions of a manufacturer who states that they are selling you a computer with an operating system, and then forces you to not only use all of their other software, but also forces you to install it only on their computers with their motherboards.

You can recover the files you need, and you can burn them to a CD, however there is some preparation that needs to be done beforehand. If you prepare an installation point, such as a folder on the partition where the operating system is to be installed, or on a second hard drive, you will need to modify one particular file, bchk32.exe, and then put in back in place of the original file.

The file, Bchk32.exe, will be found in the I386 directory of the OEM recovery CD. Simply deleting this file will not allow you to bypass the BIOS check. The file must be edited with a hex editor as described below.

The chk32.exe function:

When you execute setup.exe, it launches bchk32.exe (or launches another program which in turn launches bchk32.exe). During this progression, bchk32.exe checks the bios to determine if the computer is from a particular manufacturer or not. When bchk32.exe launches, it passes a command line argument, this argument is a directory/file name that tells bchk32.exe where to save the results of the bios check. The file name is generated randomly but always ends in .tmp (a temporary file). The specific directory where this file is saved will depend on your system (on win 95 it is “C:\WINDOWS\TEMP\”). If the manufacturers bios is detected, the file will contain “+++” (3 bytes), if it fails the test, the file will contain “—“.

If you were to view bchk32.exe with a hex editor, you will see where it stores the “+++” and “—“. When using the hex editor, if you change the “—” to “+++” so that even if system testing were to fail, the “+++” would be the result and would be stored in the file, this will work.

Using a hex editor:

Load “bchk32.exe” Go to offset/location 1F92 (hex) or 8082 (decimal) You should see “—” displayed at this location, change it to “+++”

Save the edited file using the original name

If you don’t have a hex editor, just run a search on the Internet. There are hundreds of sites that offer them as both freeware and shareware. You can also look UltraEdit-32!

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