read this ........... STOP errors 0x00000050: PAGE_FAULT_IN_NONPAGED_AREA This bugcheck indicates that invalid memory has been referenced. This problem is typically caused by one or more faulty memory modules, one or more faulty processors, buggy drivers or kernel-mode services, registry hive corruption, or paging file corruption. Parameters No. Description 1 Memory address referenced 2 0: Read operation 1: Write operation 3 Address that referenced memory (if known) 4 Reserved Troubleshooting See generic solutions 1: Memory test, 2: Scan the system drive for errors, 3: Last known good and 4: Registry roll-back. You may also need the assistance of a technician that is able to use a debugger on the crash dump file(s) (typically stored in %Systemroot%\Minidump) in order to determine which driver, service, process, or hardware device is at fault. k now how do i fix this? i can't even start the windows. everytime it goes into the Windows XP Logo then the system reboot itself again.. i can't even go into the Welcome screen. I try to use my old hard drive as a master then use the problem hard drive as a slave. However this way is not working also. when i connected the problem hard drive as a slave, it still rebooting and give me stop error message. but when i disconnect the problem hard drive and just use my old hard drive it works, i can use windows XP. my question is how do i reformat my problem hard drive?