This file is appearing with regularity as an adware and spyware related module. Many virus checkers are reporting it as a trojan. When you attempt to delete this it may not let you if the file is in use. Press ctrl-alt-del and find the rlvknlg.exe program in your processes list, then end the task. Then you should be able to delete it after doing this. Visit rlvknlg.exe for complete information on this task or process.