Windows and Early Intel 80386 CPU 32-Bit Operations

• Microsoft Windows operating system versions 2.x, 3.0, 3.0a, 3.1, 3.11
• Microsoft Windows for Workgroups versions 3.1, 3.11

SYMPTOMS

You may receive either of the following error messages when you start Microsoft Windows in 386 enhanced mode:

• WARNING: The Intel 80386 CPU in this computer does not reliably execute 32-bit operations. Windows will usually work correctly on computers with this problem, but may occasionally fail.
• WARNING: the Intel 80386 processor in the computer does not reliably execute 32-bit multiply operations, Windows usually works correctly on computers with this problem but may occasionally fail, you may want to replace your 80386 processor. Press any key to continue.

CAUSE

When Intel introduced the 80386 CPU, it released some chips that had not been fully tested using 32-bit operations. Windows checks for this to warn you that you may want to replace the CPU with one of the newer, more reliable 80386 chips.

This is normally not a problem, as most programs do not use the true 32- bit capabilities of the 80386 CPU. However, since Windows does use 32-bit operations, you may experience problems.

WORKAROUND

Windows 2.x

Two important files come with enhanced-mode Windows, WIN386.EXE and WIN86.COM. WIN386.EXE provides memory management and support for standard applications; WIN86.COM is essentially the same as Windows/286 without support for standard applications. After WIN386.EXE is loaded, it creates a virtual machine, loads WIN86.COM, and executes it.

If the problem seems to be resolved by running WIN86.COM instead of WIN386.EXE, you may need to replace the CPU in your computer. If Windows acts the same with either WIN386.EXE or WIN86.COM, the problem is probably not related to the CPU.

Windows 3.0, 3.1, and 3.11 and Windows for Workgroups 3.1 and 3.11

You must upgrade the 80386 CPU in your computer to work around this problem.

MORE INFORMATION

The Intel products discussed here are manufactured by a vendor independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability.