PSIService.exe is part of copy-protection software from Protexis. This program is installed by various software programs, and prevents you from making unauthorized copies of these programs, usually it comes with software such as corel draw.
So I recommend to keep this software running, because if you disable from startup trough msconfig, any program like corel draw will stop working and need to reinstall, but dont worry you dont need to reinstall it, just re-enable Protexis Licensing from msconfig and restart you computer.