With a dual boot, can I use programs across OS's?

I'm currently dual-booting Windows 7 and 10, with 10 being the primary. They are both installed on the same SSD, with most programs (basically anything that lets me choose the install path) being installed to a separate HDD. Space isn't the issue, just going to put that out there, it's 480GB with 240GB being allocated to each OS.

My big question is, can I possibly install them while using one OS, but still be able to run them from the other OS without installing them again? I've heard of symbolic and hard links, but I'm still confused about them and their effectiveness. I know you can use them for non-critical files, but how would that work for files used by programs? Wouldn't that theoretically cause problems?

I have a program that allows me to utilize my external USB capture device. It works perfectly for Windows 7, but on 10, some control sliders can't be modified, or the changes don't save, I forget which. Could installing that on one allow me to run it from the other? Or run something like Steam games minus minor setup?

Thanks,
Robert

Only completely portable programs- which by definition aren't installed.
And even some 'portable' programs are not truly portable in the sense of not relying solely on what's in a single folder.

Any program that is installed may have folders in a number of areas and use temporary storage in more, these being different to the designated installation folder.

Most programs use (many) registry keys and store both permanent and changing data in the registry. The registry is unique to each instance of the OS, as are the folders above.

Some programs require services to run, or even drivers.

I have a program that allows me to utilize my external USB capture device. It works perfectly for Windows 7, but on 10, some control sliders can't be modified, or the changes don't save, I forget which. Could installing that on one allow me to run it from the other?

- some older programs are incompatible with later versions of Windows. Sometimes this can be handled by using compatibility mode, sometimes they are simply unusable.
- less commonly, programs designed for Win 10, say, will not run on an older OS.

No amount of hard linking could circumvent this?

MrMii Win 10 said:

No amount of hard linking could circumvent this?

No. As Dalchina told you, only completely portable apps can be run from any location.

For you, it's one computer with two operating systems, but it actually is exactly as if they were two different computers. For instance, they are seen as individual computers on network. You cannot run a program from computer A on computer B.

Kari

Ditto Kari. Since only one OS is running at any specific time the programs have to be installed as if the other OS doesn't exist. You can usually install in the same Folder on the drive but it is the need for support files to be in the right place on each OS, Start menu items created and Registry entries made. Then each OS knows about the programs and how to run them.

Alright, well thanks for the insight everyone. Guess I'll just have to install them on each one. Thanks.

You're welcome.