Old operating system on other drive, how to boot it?

I've installed Win10 on SSD (which goes straight to motherboard) and I have an old system on SSD which is 2,5" (?) which I connect to motherboard with a cable, it's meant for laptops but never used anywhere but in my desktop. It had a working operating system but when I got a new SSD I decided to install Win10 there. Unrelated to the issue at hand I have an issue running a program correctly on this newer system, it's an audio recording software and for the life of me I cannot get the software to hear anything from line in. But the software is (and worked) on the old system so I'd like to boot that one (to get a small but important thing done) which is still intact, at least I haven't removed any system files from that drive.

How do I get Win10 to see that there is an alternative operating system on another drive?

I went to my computer --> properties ---> advanced system settings --> startup and recovery and pressed settings there. In the part where I can choose to have timer to select different systems I have the timer on but the drop box shows only this system as an option, hence no timer when booting. I'd need to somehow recover or awake the other system without messing with hardware (such as removing this active system disk, it's behind plenty of stuff I cannot dig out by my self). Also I shouldn't risk the status of this current operating system which is customized and running otherwise nicely so I'm weary of the though of running recovery/repair options on the older system, worrying that it might undermine the status of current operating system or messing up boot sectors all over the place, making this system unstable if I plug the other one physically out at some point (boot sectors crossed over multiple hard disks or something like that).

What might be going on here, why is the old system so undermined that I cannot get this windows to realize there is actually windows there too... It has two windows trees actually, windows and windows.old.

If it's relevant (and if I recall correctly) I installed my system on this new drive so that the old system drive was physically in place. What I *think* happened there was that the windows went to the new drive but boot sectors remained at the old drive. So I plugged the old drive completely out and then I managed to install this clean version completely from start (format c:) independent on this new drive. If that's the case then maybe it could be even the windows.old (on that other physical drive) I'd need to revive, again without risking harm this current one. However not sure if this is the case, keep in mind, it's been almost a year.

Any ideas are welcome :)

Thank you.

edit: Oh forgot, BIOS only gives this drive as an option too (besides usb, cd-rom and such external means...)

What is "emo"?

ignatzatsonic said:

What is "emo"?

Oh sorry, my brainfart, meant motherboard, got languages crossed there.

ScothMcBeast said:

...it's an audio recording software and for the life of me I cannot get the software to hear anything from line in. ...

What is the software? Maybe we can help to make it work...

Bree said:

What is the software? Maybe we can help to make it work...

Cubase 5.1. I've had success before with the same hardware (or motherboard rather with the same line in before).
Again guessing here but I think the fact that this is the first installment of win10 where I've had my Logitech G935 wireless 7.1 headset attached when installing Windows and maybe Windows somehow prioritized it in some way I can't figure out. If that might the factor then uninstalling software, uninstalling G935 would be something I'm willing to try at heart beat but also I'm thinking while those two are uninstalled some cleaning up needs to be done on drivers or config files before re-installing the software and trying out if it works (before re-introducing G935 to the system). But that's guessing like I said.

I get the motherboards audio card (MSI Z390 LGA1151 ATX) as an option in the software, otherwise the Z390 audio works as expected and the line in feed does monitor through but the software doesn't have any sign of incoming traffic when monitored or recorded. I'd *hope* it's just some slider that's down or a checkbox uncheck as a default outside the software which would cause my troubles - but if it is it's a new one or one I haven't dealt with in a long while. I've even used old and current Realtek HD audio managers to set levels and tweaks to try to correct this but to no avail.

- - - Updated - - -

Oh, heck. That made me think of a thing to try which escaped me (trying different ASIO driver sources in the software and tweaking Windows recording setting as well as Realtek HD manager settings one by one) and it solved it (finding the right combination of software ASIO driver, Realtek HD audio manager setting and Windows recording settings). While I feel stupid I'm taking this after a LONG headache over this one. Sorry for the trouble and thanks for trying to help!

- - - Updated - - -

Since the headline compared to solution is wayyyy off this thread prolly should be removed all together, just don't know how.

ScothMcBeast said:

That made me think...

Result

I was just about to suggest you looked in the Recording settings for Sound in the Control Panel. but you beat me too it.