Laptop won’t boot but everything appears to be ok

In summary my laptop refuses to boot despite the disk drive appearing to be ok. It boots as normal with my 80gb disk but refuses to boot with my 250gb disk. However the 250gb appears to be ok when attached in an external USB caddy.


I have a Dell 8600 Inspiron laptop. I recently replaced the original 80gb disk with a 250gb Western Digital disk, keeping the 80gb disk as a spare. Both drives have XP loaded. The new 250gb disk has been working fine since I bought it in early December.

I used it quite heavily today. I put about 100gb of data, mainly mpg video files on it, and then started playing some of the video files with VLC media player. Everything was working normally until one video started to play a bit jerkily. I didn’t know if there was a fault with the video file, or whether I was running out of Windows or processor resources so I closed VLC, closed everything else, ran ccleaner and set the laptop to restart. I run ccleaner regularly and reboot once or twice a day just to keep everything fresh.

Tonight it refused to boot. It closed down as normal and started the reboot sequence but all I got was the initial Dell screen. Instead of Windows XP loading, all I got was a blinking cursor in the top left hand corner. It doesn’t react to F2 or F12 which are the Setup and Boot menu command keys respectively. It doesn’t react to any other F key either. Ctrl Alt Delete just restarts the initial load but gets no further than before.

I removed the 250gb disk and put the original 80gb disk in. The laptop works fine with that so the problem appears to be with the 2650gb disk.

I have put that in an external caddy and my laptop can see it. It has all the files I would expect to find on it. I have run check disk and that found nothing amiss.

If the disk had failed, that would explain the problem, but the disk appears to be OK. I have swapped between the 80gb and 250gb disks a few times and each time the 80gb boots normally but the 250gb refuses to boot. Yet it works fine in an external caddy.

In the morning I will download and try the Western Digital diagnostic tools and see if that helps.

Meantime, does anyone have any helpful suggestions?

Thanks

Edit: I did try and boot with the 250gb drive in the external caddy, selecting F12 for boot options and selecting "Boot from external USB device". That just brought up a blue screen fatal error so maybe the boot files (or whatever they are called) on the 250gb disk have somehow become corrupted.