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Below is part of what it said.
What happened? (How NTLDR works and why your PC can't find it)
When your computer starts, the BIOS attempts to find the primary hard drive's active partition to read the first sector for the MBR (Master Boot Record), it uses that info to load the rest of the OS. For Windows NT4/2k/XP the MBR is pointed to the NTLDR (New Technology Loader) and it takes it from there. If you get the "NTLDR is missing, press any key to restart" what's most likely going on is the BIOS either didn't look for the right drive, didn't find the right partition, it wasn't active, didn't find the MBR, or the MBR didn't list NTLDR in the right place, the location of NTLDR changed, or you are looking at a hardware failure situation (memory/cables/drive/motherboard/etc).