Laptop lost partition - how to regain it and how to reset laptop if recovery partitio

HPMan

My dad's 7 year old laptop has begun having problems on boot up and in use. It is a former Windows 7 laptop but now is running the latest Windows 10 Home edition , 64 bit edition.
it was fine until a few months ago, then it began to have extremely long boot up times , often several hours from turn on to having the desktop appear. We do not think it has anyway to do with the monthly Windows updates as it would act "normally" at times then go extremely slow.
I have run antivirus checks from within Windows and nothing apart from Tracking Cookies have been found recently, though i understand it suffered  virus 3 years ago.
I have run Chkdsk and there have been a number of bad areas on the drive but possibly more if i ran it again.
The laptop locks up, freezes and doesnt always display desktop , program windows ,taskbar icons, desktop icons correctly , but sometimes it does.
A typical boot up can take well over an hour, may be two. Sometimes the labels for the desktop icons do not appear and sometimes the icons are small, sometimes normal sized.Sometimes we would need in the recent past use a Windows 10 Recovery ISO USB hard drive to get into Windows to get to Command prompt to run Chkdsk. Now, after many errors were deleted and bad areas dealt with, we can boot up into Windows without the USB hard disk, but we have the same problems of small icons, missing incomplete windows etc. - though it is through Selective Bootup.
When we leave it for the couple of hours we may try to go to say, File Explorer. If we are lucky and dont over task the laptop , we can see the drives listed. There is one  physical drive, it is C: local, local and F: SYSTEM. C: and F: have used and free sizes shown, does not. On boot up , it will go to Scanning and Repairing , we do not get any log or report on what it repaired if anything and when we eventually get to the Command prompt (either from inside Windows for from the USB hard disk boot up routine) we find the drive letters are all mixed up. C: could be G:, F: could be and so on. We then DIR each drive partition to get to the dodgy partition , we are told it is unreadable or corrupt. We do not know what this partition contained. Could it be a Samsung recovery partition ? What is the SYSTEM partition? How can we bring this partition back to show its contents?
We by sheer good luck did a backup using Norton Security with Backup when the laptop was in a good working "no problems at all" phase and have got all the data off we need apart from a period of a few days - it ran perfectly for a number of days, the backup was done at the beginning of this "no problems" phase. We can see these small number of letters and spreadsheets but will copy these over to the backup data disk. We did notice that Norton Security with Backup on restoring files gives a date as creation to be the restore date. This has thrown us. We shall think about dragging and dropping the documents folder from the old laptop to the data backup hard disk and then to the new laptop - will the original dates remain on dragging and dropping? Do we need to highlight all of the files then drag and drop or can we drag and drop the Documents folder itself?
Norton Security with Backup has now thrown up an error and because of the problems of incomplete screens etc we are unable and unwilling to try downloading the special Norton Uninstall program. Can we, when we are able to get into File Explorer, go and delete everything Norton related by hand? Then reboot, wait the 2 hours etc and then use Ccleaner (which has worked) to do a Registry clean out of Norton files? 
The old laptop is a bit of a project now but we would like if we can, get it up and running again even if it was just a feather in the cap. We are thinking we might do a Reset. We have a Windows 7 Product key sticker on the back of the laptop but it is now a Windows 10 laptop and by sheer good luck again, we did a belarc report in the running good phase and the Windows 10 key shown is a completely different key altogether. This has thrown us as we did the free upgrade to Windows 10 (none of us can recall if we went through Windows 8/8.1) and we thought there was no longer Product keys for Windows 10 installations. How would we proceed? What if we changed the disk for a new one, what Product key would we use? We arent too fussed about the Samsung programs, happy to have a bog standard 64 bit  Microsoft Windows 10 installation.
Any help, advice, tips, etc grately received

cheers all

ED E

Brevity is not your strong point is it?

1. Get new disk (Check if you need IDE or SATA)
2. Install Windowze again

HPMan

lol, often when i read brief postings on forums from other people , many people say they miss out crucial and pertinent information which would if they had known some particular point, the advice would had been completely different.

It still doesnt advise about the Product Key as if a new hard disk is installed, how would Windows be activated when there isnt any old Product Key buried deep in the hard disk?

Reati

HPMan wrote: »

lol, often when i read brief postings on forums from other people , many people say they miss out crucial and pertinent information which would if they had known some particular point, the advice would had been completely different.

It still doesnt advise about the Product Key as if a new hard disk is installed, how would Windows be activated when there isnt any old Product Key buried deep in the hard disk?

Detail is good. So is structure, like paragraphs.

smuggler.ie

If you able to run laptop, you can "read" product key's with produkey (download is 2/3 down the page)
Take note of all of them(OEM(win7?), win10, office, etc.).
New install Windows should be activated automagically as it reads OEM key stored in BIOS ,not drive.
If doesn't activate auto - Activate manually, use OEM key.

You can make installation media for win10 from official Microsoft site
Keep in mind - windows version need to mach OEM windows installation version.You mentioned "Home"

ED E

smuggler.ie wrote: »

New install Windows should be activated automagically as it reads OEM key stored in BIOS ,not drive.
If doesn't activate auto - Activate manually, use OEM key.

BIOS SLIC will be for W7.

W10 should profile the machine and auto activate online.

smuggler.ie

Agree, should auto activate
Have auto activated multiple Win10 fresh installs on brand new PC's with origin OS Win7Pro.
Microsoft stopped auto activating after 5ft or 6st PC - probably sensed activation request coming from same IP and locked it(not sure). Microsoft support neither confirmed locking, nor helped to resolve. Since, have to read OEM key from BIOS and use manually or auto activation works again if move to different network.