Acer Aspire 5830T 'disk read error'

Hi

I've had a problem with my laptop for a while. When I switch it on, the Acer logo comes up but it can't seem to boot the operating system (Windows). The error message is

'A disk read error occurred

Press Ctrl+Alt+Del to restart'

When I restart, it just does the same thing again. The HDD is the first thing on the boot priority order, so I don't know why it wouldn't load up. It has, on two occasions, just started working by itself, but this lasts less than a week and it's broken again.

It seems to be a common problem for people with this laptop, and it could be because the hard drive has become dislodged, but I can only guess. And that doesn't explain why it would occasionally work. Any help is appreciated!