Something went wrong and my work laptop running Windows 7 turned off without suspending when the lid was closed. Turned it back on to find that everything’s darn slow and the hard disk light is lit all the time. Shut it down and restarted a several times with the same result. Booting with a CD or a USB wasn’t an option since this is a locked machine. Some googling suggested that chkdsk would be a good idea.
So I typed in cmd at the start menu, right clicked and chose Run As Administrator. Even though I don’t have admin access, it’s possible to run an app ‘as administrator’. Then typed in chkdsk /r to the prompt and pressed Enter. The /r flag would let chkdsk locate bad sectors and try to recover readable information. It wasn’t able to run the scan then and there coz I’d booted the OS with the same hard disk, but offered to schedule the check for the next time the system restarts. Restart the machine and chkdsk would run for several hours depending on the hard disk size/speed. It took nearly 4 hours in my case and several bad sectors were recovered. After this Windows would boot without a hitch.