its a file your computer needs to boot. its the windows file your bios looks for first. you can copy it over from another computer, just copy the file from another computer. then use something like "puppy linux" or a bootable thumbdrive that boots with out the hard drive to copy it back.
this will only be useful if its the only file missing. there is a chance a lot of your drive got erased.
I tried the ehow link to get the file but it did not work the 2nd computer is on win7 and has the latest internet explorer that I am taking the file from does anyone else know any other way of getting the file?