Dom, if you buy the used laptop for 40 bucks with the bad hard drive, you just install your hard drive in it and you are done!
My Computer
At a glance
Windows 7 64 Bit Home Premium SP1i7-3820GSkill F3-14900CL9Q - 16GBEVGA GeForce GTX660 - Driver 352.86
- Computer type
- PC/Desktop
- Computer Manufacturer/Model Number
- Home Built - Jan 2013
- OS
- Windows 7 64 Bit Home Premium SP1
- CPU
- i7-3820
- Motherboard
- Asus P9X79-PRO - Bios 4608
- Memory
- GSkill F3-14900CL9Q - 16GB
- Graphics Card(s)
- EVGA GeForce GTX660 - Driver 352.86
- Sound Card
- On board Realtek ALC898
- Monitor(s) Displays
- Acer S271HL
- Screen Resolution
- 1920 x 1080
- Hard Drives
- #1- Samsung 840 Pro Series
#2- Western Digital WD1002FAEX Sata3 Black
#3- Western Digital WD1002FAEX Sata3 Black
- PSU
- Corsair CMPSU-850TX-V2 - 850 watt (by Seasonic)
- Case
- Corsair Obsidian 550D
- Cooling
- Standard 3 120mm case fans, Cooler Master Hyper 212 EVO
- Keyboard
- MS KC-0405
- Mouse
- Intellimouse 5-button
- Internet Speed
- 56 Mbits/Sec (on a good day)
- Antivirus
- Avast & Malwarebytes
- Browser
- Firefox
- Other Info
- Asus DVD - DRW-24B1ST 24X
And since its coming up to Christmas, he'll want a new computer anyway, so no point buying an old laptop all over again. I might as well buy parts off Ebay and build him a new computer (I've always wanted to build computers). 
