If you got this on Windows Vista
Windows Vista does not boot like previous versions, you can keep reading my page to boot into an existing installation of 98/NT/2000/XP, but if you have just a single Vista install and nothing else, "NeoSmart.net" has a fantastic article on "Recovering the Windows Vista Bootloader from the DVD" and an awesome program called EasyBCD. It looks like they are doing great things over there for getting the problem resolved on Vista.
If you got this on Windows XP (or Windows 2000, or NT4, or Windows 98)
Keep Reading.
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).
The first thing to do is try to change back whatever hardware or software change you just made (this could be as simple as leaving a floppy disk in the drive or you need to reseat the cables). If the contents of the drive are especially important and you have no backups, I would recommend removing the hard drive, placing in an enclosure, and backing up the data first, in fact, backup all of your computers. (What if I made new changes that I want to keep?).
Make a NTLDR boot disk to get back into Windows.
The quick test to make sure your OS installation is still good is to create an MBR and NTLDR on a floppy disk and check if you can just boot back up into your system, this disk will check many of the partitions for a working windows installation. Here are the instructions to do this:
1. Get a blank floppy/cd-r/usb (whatever is on it will be erased), and put it into a working computer.
2. If you have a working Windows machine download my fix: Floppy fixntldr.exe | CD-R fixntldriso.zip | USB ntldrusb.zip onto a working computer (Backup copies of these files available at http://ntldrismissing.com )
(What if I don't want to download a file from a website I don't trust?). (64 bit WinXP Floppy 64ntflop.exe | CD-R 64ntiso.zip | Files 64ntfile.zip)
Do you remember if the broken computers had the Windows installation in "Windows"? If you can't remember just keep going (What if it was not named Windows but WINNT like in NT4 or 2000?) .
(If your backup system is NT4 or Windows 2000: What if my backup system is Mac / Linux or another alt OS?).
3 Make the new boot disk:
• Floppy: Don't put the fixntldr.exe on your floppy drive, but the file on your desktop or anywhere on your C:\ drive. Run the fixntldr.exe file by double clicking it. Click OK to overwrite the blank floppy disc in the working computer, you should see some screens about writing a new floppy disk. (If you don't like running an exe from me, you can run fixntldr_RawRite.zip and just replace the RawRite.exe file inside with one you trust) (now go to step 4)
• CD-R: This is not a normal file you burn to a CD, it is an "ISO" file, you must first extract the fixntldriso.zip file by right clicking it and choosing "Extract All" then Next>Next>Finish then download a program called "ISO Recorder" from here http://isorecorder.alexfeinman.com/isorecorder.htm (Windows 2000 users use Active ISO Burner IsoBurner-Setup.exe) and install it. Once it's installed, right click the fixntldr.iso file and choose to "Copy image to CD" or "Burn ISO file" and let it burn the cd (now go to step 4)
• USB: Screenshots of every step of making the USB disk and boot with it Right click the ntldrusb.zip file and choose "Extract All" Next>Next>Finish Then Insert your USB Stick into the working computer (remove any other USB sticks, and be sure there isn't anything on the USB stick that you want since we are about to erase it); Double-click HPUSBFW.EXE in the ntldrusb folder; Check "Create a DOS startup disk" and "using DOS system files located at" then press the grey button with the "...";
A box will come up asking you which folder to select, point it to the "dos system files" folder;
Press OK; Press Start; Press Yes; Let it run for just a few minutes till a new box comes up; Press OK; Press Close;
Open the "putonusb" folder, copy all the files, paste them onto the usb stick (just in the root of the drive, like E:\);
Eject the USB Stick; Remove it from your computer;
Place it into the computer with the "NTLDR is missing" issue, reboot it.
You will see the Windows 98 screen pop up for a second, then you will see a black screen with white letters prompting you to "replace boot sector of the drive C: (y/n)", press the y key; (If you have a wireless keyboard that doesn't seem to work in this mode, try checking the BIOS for an option on setting up the USB connection differently)
It will go to a C:\ prompt, reboot the computer by pressing Ctrl+Alt+Del; (now go to step 4)
4 Put the new floppy/cd-r/usb you have just created into the computer that gets the NTLDR is missing error message, turn the broken computer off.
Using the boot disk in the computer with the "NTLDR is missing" error.
Power on the broken computer with the floppy/cd-r/usb inside it/plugged into it (if the computer was already on, restart it). Once your computer gets past the BIOS screen your computer should try to access the boot disk and you should see a black screen with white letters (What if I don't see this screen?). that says:
1ST TRY THIS seleccione esto primero
2ND TRY THIS essayez ceci en deuxieme
3RD TRY THIS wahlen Sie diesen Third
4TH TRY THIS selezioni questo fourth
5TH TRY THIS selecione este fifth
6TH TRY THIS seleccione este sexto
7TH TRY THIS essayez ceci en septieme
8TH TRY THIS wahlen Sie dieses achte
9TH TRY THIS selezioni questo nono
10TH TRY THIS selecione este decimo
(I threw in some Spanish / French / German / Italian / Portuguese for international flavor.)
This file is set up to automatically select the "1ST TRY THIS" choice after 30 seconds. Try it first, if it was the wrong selection, you will likely get one of these four errors:
1 Windows could not start because file "
2 Windows could not start because of a computer disk hardware configuration problem. Could not read from the selected boot disk. Check boot path and disk hardware. Please check the Windows documentation about hardware disk configuration and your hardware reference manuals for additional information.
3 I/O Error accessing boot sector file multi(0)disk(0)fdisk(0)\BOOTSECT.DOS
4 Immediate reboot
If you get the immediate reboot or some other weird error, try pressing F8 at the "1st Try This" selection screen, it will give you a prompt where you can select Safe Mode, and then try the "1st Try This" option again. Safe Mode is a special "minimal" version of Windows that doesn't load certain parts of the operating system that might have caused the problem.
One of the choices should eventually boot you back into Windows. (What if none of the options worked?).
Download FIX STEP NTLDR IS MISSING.pdf
Article source : support.microsoft.com