Stuck on an underscore character during the boot

DougFrippon

Senior member
Jan 31, 2001
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One of my friend call me this morning, he said when he tried to boot his computer as asual. During the boot, it would first display the BIOS normaly and then the computer gets stuck, only showing an underscore character topleft corner.

Problem is that he lives far from me, and I can't go check on his computer. I have absolutly no clue about what would be the problem, what would be your guess?

 

alzan

Diamond Member
May 21, 2003
3,860
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Without knowing a little bit more, I'm swinging blind but I'll give it a shot: If his system has a floppy drive there could be a non-bootable floppy in it causing it to hang; if it's a newer system and is able to boot from USB there could be a flash drive or memory card inserted that the computer is trying to boot from.

It's also possible that his boot device order in BIOS got altered and his hard drive is no longer listed as a bootable device; a more distant possibility that the hard drive is bad/dead or a RAM module is bad or not seated properly. Do you know if he gets a series of beep codes during or right after POST.

alzan
 

Lord Evermore

Diamond Member
Oct 10, 1999
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Underscore character just indicates the system is live, but can't go to the next step in the boot process, which in this case would be attempting to locate a hard drive to find an operating system (or a floppy drive or CDROM, depending on how the system is configured to boot). Or as DougFrippon suggested, sometimes a bad program on a disk can cause a hang; I can't boot to IBM's Drive Fitness Test disk for some reason, it hangs the system right after loading the OS, I believe I worked out that it is the mouse driver. Just because nothing showed up on the screen doesn't mean nothing was loaded, as the OS boot can be set up not to display progress.

Does the system attempt to read the floppy drive or optical drive after POST?

Use the key combination needed to get into the BIOS setup during POST, and check the basic BIOS settings page, make sure it shows all his hard drives and optical drives.

A physical test would be to try booting with only the floppy drive connected (means he has to open the case of course), see if it says "no operating system found" or something like that. Then try with just the CDROM, then just the hard drive, eventually you might find which one is causing the hang.