Great, thanks guys.
The laptop isn't that old, and has to date only been used a handful of times. Although I don't have a fresh copy of Windows 7 or 8, I created set up disks with W7, and then again following the W8 upgrade, so I assume these will be as good as fresh??
Re the Samsung drive, there seems to be a basic and a pro..... Basic OK? I was originally looking at the SanDisk Extreme - Samsung better?
Would the drive be a direct replacement, or would I need a different connector and mount?
Thanks again, slightly less confused now!