Do as pinkybovid suggests but rather than a system restore do a diskcheck.
To enable a disk check, go to Computer or My Computer, highlight the HDD drive, right click and select Properties from the list.
From the window that pops up select Tools and under Error checking click 'Check now'. In the next window make sure there's a tick in the 'Automatically fix file system errors' and click Start.
Windows will then say something like 'unable to check disk, because it's either locked or in use, do you want to schedule a disk check on next reboot?'
Click Yes and re-start your pc.
The Disk Check takes some time so I'd suggest you leave it on all night. As you have a laptop make sure it's plugged in to the mains otherwise the laptop will switch off and the Disk check will be abandoned.