Laptop hard drive faulty?

Hi there. I was recently given a laptop (Acer aspire 3680) to tinker with and see if I could get it running faster than it was. It was terribly slow to start up etc. After installing and running SpyBotSD and Avast and finding loads of malware and things on it it still wasn't speeding up. I then cleaned and defragged the registry as well as defragging the hard drive. Thats when i noticed that afterwards it was MORE defragged... I then thought it might be wise to run a diagnostic on the HDD. Using HDTune I found that while everything said OK and there were no disc errors the speed of the disc is about 1.4mb/s. Thats scary slow.

So my question is this: is this the last wheezing breath of a dying laptop or is there something (virus etc) that i could have missed thats eating up the laptop?

Thanks