This article was previously published under Q119118
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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.
Intel 386 microprocessors dated before April 1987 are known as B1 steppingchips. These chips are known to introduce random math errors whenperforming 32-bit operations, thus making them incompatible with Windows95.
If your 386 chip was manufactured before April 1987 or has a label on itthat reads "For 16-bit operations only," contact your hardware manufacturerabout a microprocessor upgrade.
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