CuteMouse is a DOS based, open source mouse driver, which supports many protocols of serial and PS/2 mice. It can search for a serial mouse at all COM ports or only at a specified port. An important CuteMouse feature is its small memory footprint: the resident part (TSR) occupies less than 3.5kb. CuteMouse can also install itself in upper memory, when available, without requiring external utilities such as the LH (LoadHigh) command. Modern BIOSes often make USB mice visible through the PS/2 interface if you enable "legacy" support in BIOS setup.

Microsoft Mouse Driver v8.20

Microsoft Mouse Driver v9.01