Corrupted Hal.dll (winXp) and im

hey, i have a windows xp professional at home. it had an error while booting and when i rebooted, it displayed the message "missing or corrupted hal.dll, please reinstall". i tried to look for other solutions rather than reinstalling my os because i never back-up my files. an alternative solution is replacing the corrupted hal.dll by expanding the "hal.dl_" from the installation cd to "c:\windows\system32\hal.dll" using the recovery console of the windows xp. i tried that but it keeps on saying "access denied". which means i have to log-on as the administrator first before i can alter it cause it thinks im hacking it. i cant log-on as the administrator cause i cant load windows! i tried the commands "logon" and "bootcfg \rebuild" from the recovery console but the logon command wont work cause it cant find the part where windows was installed, while the other just ends up to and error. i cant access my drive (not even copy files to another drive in dos mode) until i get log-on as administrator but i cant do that cause it cant load the winXP. im very frustrated with this thing... i need help fast!!!