Error msg in a windows 2003 server

Ladies and/or gentlemen:
I?ve got the msg: “windows has not started becouse the following file is missing or is damaged:
“\windows\system32\config\system”
to repair this file start the windows installation program fom the diskette or CD ROM; press “R” in the first display to initiate the repair.”
If I power off and then power on the system it will work ok, load the windows and run ok.
This machine has been formatted and re-instaled ok and the message continues appearing.
I am not sure if it is a HW or A SW problem.
Could somebody help me with this matter ?
I will greatly appreciate your assistance.
Thanks and Regards: Jose Y Solano