Dell restore disk won't get past user logon

Friend has a 2400 dimension. Said the hal.dll file was corrupt. As I thought copying it from my laptop and copying it into system32 would work, and it didnt, i began to try to restore the computer to its original state. however, in one last ditch effort I used my XP upgrade disk to try just to save some of her data. Well as you all know, you cant do that with a dell and even when i entered her key, it wouldnt work with my disk. so rebooted into the dell restore disk and got to the screen that says to click on any user. Except there are no users and nothing is clickable on that page at all. Through some mesh of keys i pressed, i was able to bring up a log on dialogue box but no name or password she entered would work. I even tried administrator with blank password and nothing. booted to safe mode...it then asked for admin password, which she didnt have shouldnt the restore disk just put all back to day one of the PC? I dont get why it wouldnt get past the click user window and why it asked for admin password in safe mode (i was going to try to set up user accounts thru there any better way to use the restore disk and will it work if i just format c:?