Windows 3.1 build 031

Windows 3.1.031 is mentioned in an internal Microsoft e-mail from July 1991. . The e-mail first discusses the performance of Microsoft's new disk caching program called SmartDrive (codenamed Bambi) compared to other popular disk caching programs at the time.

The e-mail then also shows results from comparing performance of Windows 3.1.031 to pre-release versions of IBM's OS/2 2.0 (version 6.138, though 6.149 is also mentioned early on). The results indicate build 31 performed better in most tests than OS/2.