If you feel the need to make your laptop run faster. Don't replace the hard drive. Simply back up what you need to a dvd cd or external hard drive, and reformat your laptop. buying a new hard drive would be irrational and pointless. It would be costly to do that and instead you could simply reformat it which would serve the same cause.Back up memory > Reformat Laptop > Be happy.P.s. The purpose of your computer slowing down could be caused by unknown viruses, infections and technical problems. Download Ccleaner and/or other virus scanners to clean up your laptop. Use this -http://majorgeeks.com/downloadget.php?id=4191&file=15&evp=a12d758b021af1a4f0a6bfe45b0c7a82And this -http://majorgeeks.com/downloadget.php?id=2471&file=15&evp=2470f9bfb0cc682334ff8c4459556118I hope you enjoyed the advise. and your laptop gets fixed!- Yours truly, Big Ben