Grey bars showing during a very slow boot process

Hello

When a PC is reaches the stage when it is supposed to start displaying the XP loading screen, mine doesn't.

Instead the screen goes black for a minute and then displays small grey bars spaced out equally straight across the bottom of my screen. It seems to be a progress bar because very slowly it starts to fill up from left to right. However, after reaching about half way, it then moves on to the loading personal settings screen.

I think I know what it is doing because when I boot into Safe Mode, it takes the same time except it displays the boot and system files that are being loaded instead. I know this is normal, however, instead of seeing them whiz down the screen, mine currently takes about 3 seconds for each one to be displayed!

Does anyone know what the problem is and what should I do to find and sort the problem?

Thanks for your attention and any advice you can give me.

That's just it, I haven't.

However, what did happen was the PC crashing for no apparent reason and from then on it has been like this. In fact it refused to boot at all so I initially I had to install XP on another hard drive to recover my own files (no back up!) but for no apparent reason again, it began booting but slowly.

Is there any way of cleaning the boot files (purging?)?

Is there a possibility that the disc could be damaged?