This is the Sony Ericsson D750i/K750i USB Driver version 126.96.36.19903 which was released in 2006. If you need an updated driver then check the website of Sony Ericsson for more details. Also note the operating system for this driver. If you cannot run it then run the file in compatibility mode.
The the installation is standard with all mobile phones. See the listing here for the instructions. note the driver Id for this file being as follows:
SEMC.Comm.Desc = “Sony Ericsson 750 USB WMC Device Management (WDM)”
UpperDescription = “Sony Ericsson 750 USB WMC Device Management Drivers”