XP system files

Have a pc running xp pro and every so often on boot up you get a dos looking screen saying it can’t boot because ********* file is missing or corrupt.the first few times it was the c\windows\system32\windows\config file and last time it was windows root>\system32\hal.dll and it has been one more different one which I can’t remember…..any ideas, sick of re-installing it or trying recovery console…..
HELP!