Flashing White Line on Boot Up

Hello

Recently i did a total rebuild of my laptop. This included formatting the drive and re-installing xp pro. All drivers are upto date. The system worked great up until last evening when i attempted to boot the machine. It went past the dell logo sign and no further. Just left a flashing white line on the upper left hand side of the screen.

It will eventually boot up after 5 or 6 attempts. I'm thinking this is a Harware issue and may have something to do with the BIOS. So i may attempt a BIOS update. I do not have much experience with the BIOS but understand it's basic fucntion.

Has anyone seen this type of problem before?

Also why does the BIOS need to be updated?

Thanks in advance for any comments

Steve