Some good advice already. I would try the following if you have some sort of USB storage device knocking around and a friend with a CD writer.
On a friends PC Download an Ubuntu LiveCD image and burn it off
Boot up said laptop from the LiveCD whilst have the USB storage plugged in
Once in Ubuntu, copy all your valuable data from your dodgy HD to the USB storage
Wipe and re-install the latop
Copy your data back
(more detailed guide here
http://www.howtogeek.com/howto/windo...dows-computer/)
May sound a bit extreme (wipe & re-install), but at least then you are starting with a known-good installation.
Also, I would agree with watercooled and recommend spinrite (grc.com/sr/spinrite.htm). In some cases, if the problem is caused by corruption from bad sectors etc. a spinrite repair will just fix your problem flat out), but even if it doesn't it will cordon off bad sectors from re-use.