Unfortunately I think the price + lack of warranty may be shooting you in the foot, I have had similar issue selling mainstream to upper notebooks without a warranty. Had it had some time left I think you would have a better chance. ...
First off it being a 3.0GB drive has nothing to do with the slowdowns, if the system does not support 3.0 the hard drive will just run at 1.5GB as its the SATA bus's limitation. Worse case it transfers files at the same speed as your...
I would check the temps on it and see if its overheating, use compressed air and blow out the vents, and prop a book under it in the back to raise the deck off the table/desk and run it and see if it continues. If it does, may be a bad...
You sure that was a "new" laptop and not a refurbished? These are no longer in production, like at least 1.5 years. And if you dont mind me asking how much did you pay for it (new would be 1500+ HP refurb 875-900).
Also and...
Go to the following link
http://h20180.www2.hp.com/apps/Nav?h...&lang=en&cc=us
Cut and paste the above in your browser if clicking doesnt work, select your model and start an online chat with support, tell them you created one...