Pakistan :: HP Hard Drive7777777777777777777

My HP DV9700t laptop that I purchased from HP's website last June stopped working recently. Unfortunately it is no longer under warranty. HP tells me that I need to purchase a Hard Drive from them (it's a 120GB, 7,200 RPM Seagate 2.5 laptop HDD) because on the windows vista recovery disk, that the hard drive serial number is inside and that it won't install onto a hard drive bought from Newegg (for example). I'm wondering if this is true. They sell their hard drives for $121 bucks while Newegg sells them for half that. HP Support told me that if I bought a HDD from someplace else I would then have to buy a retail version of Windows Vista. my HP did not come with a Windows Disk or Restoration Disk, only a Restoration partition, so they would be sending the 'Restoration Disk'.