Problem with bootup; very slow with repeated errors

Hello,

My laptop froze today while making some rhythmic noises which I would assume were coming from the harddrive. When I restarted the laptop, I heard this noise again and saw lots of errors in the startup log. Also, it took forever to startup. Below is an error that kept repeating in the /var/log/messages log. Does anyone know why this is happening, and know what I can do to fix this?

Many thanks,
David

ata1.00: failed command: READ FPDMA QUEUED
ata1.00: cmd 60/08:08:4d:3e:ad/00:00:00:00:00/40 tag 1 ncq 4096 in
         res 51/40:08:4e:3e:ad/00:00:00:00:00/40 Emask 0x409 (media error) <F>
ata1.00: status: { DRDY ERR }
ata1.00: error: { UNC }
ata1: hard resetting link
ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
ata1.00: ACPI cmd ef/02:00:00:00:00:a0 (SET FEATURES) succeeded
ata1.00: ACPI cmd f5/00:00:00:00:00:a0 (SECURITY FREEZE LOCK) filtered out
ata1.00: ACPI cmd ef/5f:00:00:00:00:a0 (SET FEATURES) succeeded
ata1.00: ACPI cmd ef/10:03:00:00:00:a0 (SET FEATURES) filtered out
ata1.00: ACPI cmd ef/02:00:00:00:00:a0 (SET FEATURES) succeeded
ata1.00: ACPI cmd f5/00:00:00:00:00:a0 (SECURITY FREEZE LOCK) filtered out
ata1.00: ACPI cmd ef/5f:00:00:00:00:a0 (SET FEATURES) succeeded
ata1.00: ACPI cmd ef/10:03:00:00:00:a0 (SET FEATURES) filtered out
ata1.00: configured for UDMA/133
ata1: EH complete

If the noise is coming from the hard drive it is most likely bad sectors. The tick tick tick is the drive trying repeatedly to read one or more sectors.