computer won't boot

Hi,

I've having issues with my computer.
It just stopped working. So i've tried a number of things but nothing has changed.
What happens is it goe's through the usual boot sequence. finds all the drives. then when it beeps insted of continueing to load it just sits there with a blank screen and a single underscore on the screen. Anyone got any Ideas?
thanks
Trev

i have repaired atleast 25 computers over the last month with the same trouble, the only way i could fix it was by using a secure erase program on a boot floppy, low level format ,wipe everything back to raw disk. then set the patition back up and format and install. i can boot up a different machine with the drive as a slave and copy files, which seem to be fine, ie favorites, emails,...ect. i assume it is either a boot virus or a windows update causing this. have never detected a virus with any scanner. tried every means i could think of to repair or fix the os, this was the only way. fdisk did not help, just deleteing the partitions didnt help, had to full erase the drive. good luck, hope this helps some.