Hard disk sentinel reporting critical health error in HDD

[acerninetes]

Recently my computer has been failing to find my hard drive every three or four times I switch it on - a minor annoyance but restarting has always fixed it this far. I've also noticed that video playback from the hard drive as well as game cut-scenes from games stored on the hard drive freeze for up to 10 seconds possible five or six times a day, which prompted me to use the demo version of Hard disk sentinel to check my disk.

This was the outcome:

The result of a random seek test:

What does all this point to? Do I need to get a new hard drive?
Thanks!

EDIT:
I've already tried changing SATA ports on the motherboard as well as using a different SATA port, to no avail.

 

[kawininjazx]

Here is some advice, if you think your hard drive is bad or have a good reason to know it is, replace it. Always keep your data backed up.