Black screen with white blinking underscore, means....

By pioneerx01 ยท 78 replies
Feb 25, 2008
  1. I am getting Black screen with white blinking underscore, and we just keep playing the staring contest (I loose). What does that signify?
  2. wanna be geek

    wanna be geek TS Rookie Posts: 80

    Well, it could mean a few things... Are you running XP?????
    Did the computer boot before???
    Did you do anything to it???
    Most of the time your boot file is corrupt.
    It could be a bad IDE cable.
    Or your hd is fried... I don't think that is the case this time...
    Try booting off of your OS disk if you are using XP and do a repair.
    It is hard to give you a specific answer without more info, but your prob is not too big of deal once you tell me more...

    OK, I took a look at your sys specs....
    Unhook your slave, hook up your master and try to boot...
    If that don't work, leave it as it is and try using a good cable...
  3. pioneerx01

    pioneerx01 TS Guru Topic Starter Posts: 277

    Yes it is XP.
    Computer was running 100% perfectly and unbeautifully till about 3 days ago. SInce then it boots about 1/5 attempts.
    I did not do anything to it for past few months.
    It could be boot file, I will investigate. (any ideas on quick fix or diagnostics)
    IDE cables are new as of yesterday.
    HDD's are all ok.

    That is the problem with more info I don't know what is really wrong or what else to tell you...


    2.5 CeleronD
    2x 512 DDR2
    3x HDD's
    128MB 4000 Nvidia

    my signature will explain a lot of
  4. wanna be geek

    wanna be geek TS Rookie Posts: 80

    Insert your Windows XP CD into your CD and assure that your CD-ROM drive is capable of booting the CD.
    Once you have booted from CD, do not select the option that states: "Press F2 to initiate the Automated System Recovery (ASR) tool." You're going to proceed until you see the following screen, at which point you will press the "R" key to enter the recovery console: [​IMG]

    After you have selected the appropriate option from step two, you will be prompted to select a valid Windows installation (Typically number "1"). Select the installation number, (As mentioned, "1" in most cases), and hit enter. If there is an administrator password for the administrator account, enter it and hit enter. You will be greeted with this screen, which indicates a recovery console at the ready: [​IMG]

    Continue to page 2 to proceed with the repair functions.

    Proceeding With the Repair Functions
    There are eight commands you must enter in sequence to repair any of the issues I noted in the opening of this guide. I will introduce them here, and then show the results graphically in the next six steps. These commands are as follows:
    C: CD ..
    C: ATTRIB -H C:\\boot.ini
    C:ATTRIB -S C:\\boot.ini
    C:ATRIB -R C:\\boot.ini
    C: del boot.ini
    C: BOOTCFG /Rebuild
    C: CHKDSK /R /F
    To "Go up a directory" in computing is to revert back to the directory above the current folder you're operating in. If, for example, I'm in the C:WINDOWSSYSTEM32 directory, and I want to get at a file in the WINDOWS directory, I would merely type CD .. and I would be taken out of the SYSTEM32 folder and up one level to WINDOWS. We're going to do the same thing here from the WINDOWS folder to get to the basic root of C: [​IMG]

    Now that we are at C: we can begin the process of repairing the operating system and that begins with modifying the attributes of the BOOT.INI file. Briefly, BOOT.INI controls what operating systems the Windows boot process can see, how to load them, and where they're located on your disk. We're going to make sure the file is no longer hidden from our prying eyes, remove the flag that sets it as an undeletable system file, and remove the flag that sets it as a file we can only read, but not write to. To do this, we will issue three commands in this step:

    to remove the Hidden, System and Read Only flags.[​IMG]

    Now that we've modified the attributes for the BOOT.INI file, it's up for deletion. The syntax for it is simple: { DEL | FILE NAME }, e.g., C:DEL BOOT.INI deletes the BOOT.INI file.[​IMG]

    Now for the most important step of our process, the BOOTCFG /REBUILD command which searches for pre-existing installations of Windows XP and rebuilds sundry essential components of the Windows operating system, recompiles the BOOT.INI file and corrects a litany of common Windows errors. It is very important that you do one or both of the following two things: First, every Windows XP owner must use /FASTDETECT as an OS Load Option when the rebuild process is finalizing. Secondly, if you are the owner of a CPU featuring Intel's XD or AMD's NX buffer overflow protection, you must also use /NOEXECUTE=OPTIN as an OS Load Option. I will demonstrate both commands for the purpose of this guide, but do not set NOEXECUTE as a load option if you do not own one of these CPUs. For the "Enter Load Identifier" portion of this command, you should enter the name of the operating system you have installed. If, for example, you are using Windows XP Home, you could type "Microsoft Windows XP Home Edition" for the identifier. This gives the process some authenticity, if you're keen on being a perfectionist.
    I can't put the last screen shot in cause I am limited to 6 but if you made it this far you should be good to go.

    This step verifies the integrity of the hard drive containing the Windows XP installation. While this step is not an essential function in our process, it's still good to be sure that the drive is physically capable of running windows, in that it contains no bad sectors or other corruptions that might be the culprit. No screenshot necessary here! Just type CHKDSK /R /F at the C:> prompt. Let it proceed; it could take in excess of 30 minutes on slower computers, when this is finished move on to the seventh and final step.

    This last step also requires no screenshot. When you are at the C:> prompt, simply type FIXBOOT. This writes a new boot sector to the hard drive and cleans up all the loose ends we created by rebuilding the BOOT.INI file and the system files. When the Windows Recovery Console asks you if you are "Sure you want to write a new bootsector to the partition C: ?" just hit "Y," then enter to confirm your decision.
  5. pioneerx01

    pioneerx01 TS Guru Topic Starter Posts: 277

    Holy Crap, thanks for the post, but unfortunately it is not going to be necessary. You were right. The boot sector(s) were bad. first 4GB's of the HDD had multiple sector failures, so "r" will not help in this case. I had to reinstall Windows outside the first 4 GB's and hopefully it will work fine now. Thanks for your help. It is always good to get an outside opinion.
  6. wanna be geek

    wanna be geek TS Rookie Posts: 80

    You are welcome... That is what we are here at this site for. Glad to help, come bck anytime to share.
  7. AndrestheBean

    AndrestheBean TS Rookie Posts: 207

    i have the same problem

    (black screen with blinking underscore)

    what can i do to fix it.
  8. pioneerx01

    pioneerx01 TS Guru Topic Starter Posts: 277

    well, it could be bad sector on the HDD that is being utilized during the boot sequence. (that was my problem). Do you have anyway of testing it? Also read the responses of others to this problem, you might find a solution there...

    Also how old is your HDD?
  9. AndrestheBean

    AndrestheBean TS Rookie Posts: 207

    i have one probblem.... i dont have the xp cd :(

    and it does not say how old the hardrive is on it
  10. kimsland

    kimsland Ex-TechSpotter Posts: 14,523

    This one is free ;)
  11. AndrestheBean

    AndrestheBean TS Rookie Posts: 207

    ok, i have to burn this image to a cd right?
  12. kimsland

    kimsland Ex-TechSpotter Posts: 14,523

  13. AndrestheBean

    AndrestheBean TS Rookie Posts: 207

    no i have infrarecorder (its free too)

    before i waste a disc

    i made a ubuntu linux cd ( as a alternative os since i didnt have the recory disc)

    and nothing happened.
  14. pioneerx01

    pioneerx01 TS Guru Topic Starter Posts: 277

    yes it might help to use the recovery Disk on the OS, but if he has messed up sector on the HDD what is he going to recover? there still will be the sector that he will get hanged up on. Any thoughts?

    Also, how old is your PC, that should estimate the age of the HDD.

    And since you are burning image to your disk can we assume you have another PC to your disposal?
  15. AndrestheBean

    AndrestheBean TS Rookie Posts: 207

    yeah i have a desktop pc.

    im not sure how old it is

    so do you think i should burn the image kim provided?

    also (when i turn on the pc it just shows the toshiba logo and the straight to the black screen and blinking underscore)
  16. kimsland

    kimsland Ex-TechSpotter Posts: 14,523

    Actually I was just trying to add to support help above, but you could do this

    Please run Memtest on your Ram
    Please run a Drive Diagnostics on your HardDrive
  17. pioneerx01

    pioneerx01 TS Guru Topic Starter Posts: 277

    I did not mean to bash your idea, it just seemed to me that if he attempts the recovery and the HDD has bad sector(s) it still might not work. Personally I would check the HDD just in case
  18. AndrestheBean

    AndrestheBean TS Rookie Posts: 207

    do i burn them on different discs?
  19. pioneerx01

    pioneerx01 TS Guru Topic Starter Posts: 277

    memtest - yes
  20. kimsland

    kimsland Ex-TechSpotter Posts: 14,523

    Actually I think it's more likely Hard Drive
    Sometimes just re-seating the Hard Drive and Ram, may be all that's required.
    Otherwise make the discs
  21. pioneerx01

    pioneerx01 TS Guru Topic Starter Posts: 277

    pardon my ignorance but what is "re-seating"?
  22. Hemantdhyani

    Hemantdhyani TS Rookie Posts: 38


    We get a blinking cursor when cust is not able to locate the oprating system- And when its blinking it is searching for the os- If u leave the computer on the same for a long time it will boot back to the desktop screen-
    Posible resons- If there is any external hard drive / Flash drive / Even if a usb printer can cause the same issue- to get it fixed accessed BIos and look for an option for boot other device and change it to disable-
  23. AndrestheBean

    AndrestheBean TS Rookie Posts: 207

    ink i will burn the discs....

    i have tried removing and the hardrive and then putting it back.
    and the sam with the ram, and still got the screen.

    i dont have any discs now but i will buy some tommorrow and try it,

    please get back to me when i put up the results

    another thing i cant access bios,,,

    i trid holding esc (like i usually accessed bios before) and nothing
  24. Hemantdhyani

    Hemantdhyani TS Rookie Posts: 38


    Reseating is removing a device or a cables and reconnecting the same-
    Like u remove the memory form the computer and put it back in- Its reseating the memory to make sure its installed correctly
  25. AndrestheBean

    AndrestheBean TS Rookie Posts: 207

    i created the cd to do the drive diagnostic and nothing happened
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