combined multiple hard drives help/advise


hope i`m posting in the right/best place for this.......

i bought a custom built pc quite a number of years ago which came with 2 physically seperate hard drives that were combined to work as one purely for storage on windows 7,
they`ve been left/used like that ever since until i recently upgraded to windows 10, they now can`t be recognised as one hard drive on windows 10,
i`m not sure if they were set to work as one drive through windows 7 or through a raid setting,
the guy who upgraded windows for me tried a recovery on only one of the 2 drives as the other would`nt even register, he recovered a load of stuff but it`s like 99% unreadable by the looks.

sooo......wether they were combined through windows 7 or through raid would there be any way of being able to recover any or all of the data that was on them?

nothing went wrong with the hard drives so all the data is there between the 2 of them as it was before the upgrade, it`s just a question of if they can be seen/read as they were on windows 7 some way/how.

thank you.
Firstly, in the interests of full disclosure, I am not a Windows person.
That being said, computers are computers and the name or title for your original circumstances where you present more than one disk as if it is a single one is called "Logical Volume Management". (LVM)

There are basically two ways of skinning the LVM cat:-

1. Have the operating system handle it for you
2. Have the firmware/BIOS/EFI handle it for you

Suggest that you look at trying to establish which is being used in your case.
As always, make sure that you have good backups of all and any data that you wish to keep.

Start with the firmware/bios/efi. You enter this by holding down a particular keyboard key when a machine is starting up from cold. The relevant key will be displayed briefly on the initial splash-screen whilst it is being powered-up from cold. You might find that you need a couple of goes at it before you can get the machine to launch the management console for the bios. Once there take a look to see if the bios can see all of the physical disks and whether there is any obvious control of the hardware going on there in the way of a raid controller and what basis that is being done.
If it just looks like a bunch of hardware components all attached to each other, chances are that Windows has traditionally/historically been used to control things, in which case boot into windows, find 'computer' somewhere in say the file manager or explorer (or wherever microsoft are hiding it this week), and then right-click and then Manage. You will then have a few choices and you are looking for something to do with 'disks', so click on that. You will then be presented with windows' version of the disk management console for all attached disks. Here you can mount, format, raid etc etc etc

A final word of caution - - - you can cause irreversible damage to data if you get this wrong. OK, so if the worse comes to the worse it's only really a case of a fresh reload of windows, but you certainly can destroy all and any data on a disk using any of those things mentioned above.
Firstly, I'd say whoever upgraded the system hadn't any sort of clue what they were doing and have now gave you an uphill battle,
Its is always a lot more difficult to add an automount HDD in windows than it is to have it there on install.
As @xero50 says, first check and see if its a BIOS or SW/FW system/RAID ,