Failing hard drive?

For the last couple of weeks my laptop has been running CHKDSK every 2-3 days and has been identifying various errors (corrupt files, orphaned files, index errors etc) and tells me that I have somewhere between 180 and 240KB in "Bad Sectors". The laptop seems to run OK after CHKDSK is finished.

Does this mean that my hard drive is beginning to fail? And if it is, how do I identify exactly which hard drive I need to buy as a replacement? I have a Dell laptop and the memory is 6GB. Is there a way for me to order the correct replacement hard drive from here please?

Thanks in advance for any help with this.