Windows 95 Fails to Install on an 80386 Computer

Last reviewed: May 30, 1996
Article ID: Q119118

The information in this article applies to:

Microsoft Windows 95

SYMPTOMS

The Windows 95 Setup program fails or displays the following error message:

   Setup error B1: Setup has detected an 80386 processor that is not
   compatible with this version of Windows. Before you can run this
   version of Windows, you need to upgrade your processor. Contact
   your computer manufacturer for more information.

CAUSE

Intel 386 microprocessors dated before April 1987 are known as B1 stepping chips. These chips are known to introduce random math errors when performing 32-bit operations, thus making them incompatible with Windows 95.

RESOLUTION

If your 386 chip was manufactured before April 1987 or has a label on it that reads "For 16-bit operations only," contact your hardware manufacturer about a microprocessor upgrade.

MORE INFORMATION

The product included here is manufactured by a vendor independent of Microsoft; we make no warranty, implied or otherwise, regarding this product's performance or reliability.

KBCategory: kbsetup kberrmsg kbhw
KBSubcategory: wpp95 win95 diskmem winboot
Additional reference words: 95 MHz locks freezes hangs err msg 16 20
dx compaq deskpro 386/20 b-step

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Last reviewed: May 30, 1996
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