The machine in question is running Windows XP Home sp2, displayed a message stating the software registry hive files were missing or corrupt appeared and would lock the machine. I booted to the recovery console, and managed to replace the file in c:\windows\system32\config with a good copy from the system volume information directory. This allowed me to get to the windows login screen where users can select their icon and enter password information. However once at that screen, there is no power any usb device plugged in, and the machine does not have any ps2 ports. I was able to do all the work in the recovery console via the same usb keyboard and mouse that aren't working once the login screen is reached. I have tried replacing the system hive file to no avail. The problem also occurs when trying to boot to safe mode, and choosing last know good configuration doesn't help either. Any help would be greatly appreciated.