Himem. sys

When I turn my computer on i am getting the following error message—Himem. sys has detected unreliable XMS memory at addresses 01c0594A XMS DRIVER not installed.Where can i found this driver.I have tryed to boot it in the save mode & the computer tell me to hit CTRL+ALT+DEL TO RE-START THE computer but the computer sill will not boot up it goes back to the begining about the XMS DRIVER.