Support Required! Macbook Pro circa 2010/2011

Hi Guys

Im wondering can anyone help me

I am attempting to repair a friends macbook pro - i am extremely familiar with Laptops/Desktops but this is my first go on the Mac - it seemed a pretty straight forward situation - i took the hard drive out and tested it in my desktop - Hard Disk Sentinel reported an ungodly amount of bad sectors, and stated that drive would fail soon - recommended immediate replacement

Purchased a WesternDig 500GB drive - things were complicated by the fact that my friend lost her recovery disks - but after checking about online i realized that 'internet recovery' was possible - i executed this and sure enough the macbook downloaded the appropriate software - however disk utility refuses to format/partition/<do anything> with the new drive

- When formatting the macbook simply sits there saying that it is formatting - for 16 hours at one point

-Checked the new drive - as suspected the drive is in working order and HD SENTINAL reports as perfect

-Windows showed a corrupted File table which i deleted, leaving un partitioned space

-Tried Internet recovery again - this time reports 'Unable to unmount the disk'

I then decided to attempt to put win 7 on using my own media, even to prove that the macbook is working

-Windows installer will not install on the drive, despite it being perfect - states the drive is 'not designed to be booted from

QUestions - Am i missing something RE internet recovery? replacing a hard drive with this option seemed ideal

Is there a reason why it is not possible to install windows 7, from dry on a macbook pro? am i doing something wrong?

Mac Tech support were decidedly unhelpful just stating its old, dump it, buy a new one - my friend would be delighted to have it up and running with ANY OPERATING system at this stage as it saves her having to purchase new hard ware

Thanks in advance - the new drive is DEFINTELY not faulty - and the Macbooks memory/ram is also fine