Windows 3.0 does not correctly save and restore the emulator state for emulator functions 0x38 through 0x3E. This means that Windows applications that use a floating-point emulator other than WIN87EM.DLL may not run successfully if another application that is using WIN87EM.DLL is also running.
Windows 3.1 does correctly save and restore the emulator state. Therefore, applications that use other floating-point emulators should be run only under Windows 3.1.