Dual Boot Win 7 & Win 10 on two sperate ssd's

No you cannot.
Your Win 7 license is consumed with the Upgrade to Win 10. You can't use both on one license.

???
He has 1 Win 7 license that will be Upgraded to 10.
You can't continue to use that Win 7 installation license, clone or no clone.

If he purchases a Win 10 on its own, sure. But not the two OS's with a single license.

Based upon the OP's present configuration as he has described it and his/her intention to create this new configuration as he/she has described it, have you personally encountered a problem with the Win 10 activation process as I have described it?

Yes.
Creating a clone of an OS does not create a second 'license key'. That original key becomes null and void after a period of time. In this case, probably 30 days.

The Win 7 (or 8/8.1) license is consumed with the Upgrade to Win 10. It becomes part of the Digital Entitlement.


1 OS install and license.
Create a clone of that on a different drive.
Upgrade that Clone to Win 10.

It is still "1 license". You don't get to continue to use both.
Of course, if you keep that original Win 7 completely offline, then yeah, I guess you could. But don't connect for any updates.

When you responded "Yes" to my question as to whether you have *personally* encountered a problem with the OS activation process under the OP's situation and the circumstances I have described re the activation process, would you be good enough to recount the problem(s) you encountered?

Did you receive a Microsoft error message at any time indicating the Win 7 OS installation could no longer retain its activation status since it did not now possess a valid Product key?

Did you encounter some difficulty going online with the Win 7 installation and utilizing the OS as always?

And any problems with the Win 10 OS?

And when you checked the activation status of both OSs, was there any indication one or both were not activated? Did not both OSs indicate they were "activated"?

Any problem downloading/installing updates for either OS?

On my "personal" machines? No. Because I never felt the need to try to circumvent the system, and I like my systems running with as little issue as possible.

On other peoples machines that I have walked through the process, touched and worked on the PC?
Yes. Here, and coworkers/friends.

The original OS (Win 7 in this case) eventually reports as 'unactivated', and 'Not Genuine'.
Just like installing Win 7 with no license key, and after 30 days it starts the Unactivated nag process.

The original license is consumed into the Win 10 license, no matter how many clones you make from it. It is still one and only one license.

But I invite the OP to try it.
See what happens.
Report back here in a month or two.

USAFRet:
You indicated that the "unactivation" process re Win 7 starts about 30 days following installation of Win 10. While I don't have the precise dates handy, I know that we've performed a number of the installations referred to since the beginning of the year and to my knowledge haven't encountered any problem to date re the activation process involving either OS.

Have you come across a MS or other reliable reference to this 30 days "grace period"? Or was this just a general assumption on your part?

Using the Admin. Command Prompt in Win 7 (& Win 10): slmgr /xpr
the system returns "The machine is permanently activated." How would you account for that?

You have several systems running both Win 7 and Win 7 Upgraded to Win 10 (dualboot), from a single Win 7 license?
And it all remains working 100%?

The 30 days relates to the Rollback period of Upgrading from 7 to 10. After 30 days, according to MS, you can't go roll back. Given a Retail Win 7 license, you can reinstall that Win 7, but you don't get to continue to use the Win 10.

Also, the original Win 7 30 day 'grace period' after install.

This Upgrade to Windows 10 is not a 'free' new OS. It is Upgrading your old OS.
Just like Upgrading your Vista license to Win 7. But back then, you had to pay for it. It was much cheaper than buying Win 7 on its on, but you did not get to keep both.
Here, the difference is that it is a 'free' Upgrade. It is still one license. One use.

USARET:

As long as you have a valid Product key for your present activated Win 7 installation I really don't think it was necessary for you to purchase a new key for what would be an upgraded Win 10 installation. If it would develop that at some future date activation problems would arise (as USARet has indicated), then you could purchase the required license at that time. On the other hand if you feel comfortable now having a separate Product key for your Win 10 installation, so be it.

As to your current questions...

Yes, you can fresh-install the Win 10 OS on your new SSD as you have described.

As to booting to one or the other OS...
All our desktop PCs contain external mobile racks for removable HDD/SSDs, so we can install multiple OSs on different drives. A simple press on the ON-OFF power button will boot the system to the desired drive. These mobile racks (usually we install one or two) are installed in the PC case's external 5 1/4" bay just like an optical drive would be installed. We wouldn't build a desktop PC without them.
See http://www.newegg.com/Product/Product.aspx?Item=N82E16817995104 for an example of the type of mobile rack we generally use. (Although designed for a 3.5" HDD a simple modification is all that's necessary for the removable tray to accommodate a SSD (2.5" disk).

I mention this device in the event you may be interested at some point.

I'm not sure the F8 process will work to select the desired boot disk. You'll just have to try it.

Assuming the SSDs are MBR-partitioned, you can use Disk Management to select the sub-menu option "Mark Partition as Active" after right-clicking on the drive's schematic in DM. The MBR-partitioned drive must be "Marked as Active" in order that it will boot. So it you wanted to boot to the Win 7 installation you would mark that drive as indicated. Ditto for the Win 10 installation.

If you use that process the "other" drive will be detected as a secondary drive when the boot is made to the "Active" drive. So you could use DM to mark Active the secondary drive if next you wanted to boot to that drive instead of the drive you just booted to.

Now there are third-party boot loaders that you probably could use and probably are more practical. We don't use them so I can't make a recommendation. Do a Google search. Perhaps other users will weigh in here with their recommendations.

P.S.
Beginning tomorrow (6-11) I will not be available for the next few months. Good luck.

No, you don't need them, but keep them in mind for the future.

For the future, here's a more detailed description of those devices and why we're enthusiastic about the. We've prepared this description for members of our local computer club.

I can virtually guarantee that you will never regret installing one or more mobile racks in your desktop PC to house one or more removable HDDs or SSDs.

Just about every user we're aware of who uses this type of hardware configuration hardly ever returns to the "old way" of installing their HDD(s)/SSD(s) internally in their systems.

Consider the advantages...

1. The beauty of installing removable HDD/SSDs in a desktop PC is that the user can easily work with multiple installed drives, each effectively isolated (when desired) from any other installed drive. Thus, multiple operating systems may be installed on different drives installed in the system and no conflicts will arise from this situation since each drive can be completely isolated from another drive. In addition, the use of removable drives facilitates accommodating different storage/backup needs that the user may desire since it's a simple matter to add, remove, modify a HDD/SSD using a removable drive in the system.

2. Through a simple turn of a mobile rack's keylock or pressing its power switch, the user can thus boot to this drive or that drive without the need for any "bootloader" or any other multi-booting software, as well as avoiding the need (in most cases) to access the motherboard's BIOS to change the boot priority order in order to boot to this or that particular HDD that contains a different OS.

3. With removable HDD/SSDs desktop PC users have an UNLIMITED number of drives to work with should they choose without the need for opening their computer cases to install (or remove) the drive in the machine. Again, each removable drive is isolated from other drives at the user's option.

4. Should a removable HDD/SSD become defective/dysfunctional and need to be removed & replaced in the system, it's a simple & quick process for a user to remove & replace it from the comfort of his or her computer chair.

We've been particularly partial to the Athena Power MR-125PB model that I mentioned above...
http://www.newegg.com/Product/Product.aspx?Item=N82E16817995104
As of June, 2016 - $14.99 + 2.99 shipping = $17.98

The mobile rack is a two-piece affair - the removable tray and the rack itself which is affixed to the desktop PC's 5 1/4" bay (identical to affixing an optical drive or some such 5 1/4" device).

An enormous advantage (for us) of this particular mobile rack is that unlike most HDD/SSD mobile racks that are on the market, the Athena Power model is equipped with an ON-OFF power switch button, a most desirable feature in our opinion. Assuming a user is working with multiple removable hard drives in their mobile racks (or has also installed a fixed internally-connected hard drive), it's a simple matter to press the ON-OFF button and "on-the-fly" temporarily disable one or more of the mobile rack's hard drives without the need of using the rack's lever to remove the rack's tray (caddy) containing the HDD from the rack's internal SATA power/data connectors.

Of course should the user choose to do so it's a relatively simple matter to press the removable tray's lever release button and thus physically disconnect the removable tray containing the tray's HDD/SSD SATA data/power connectors from the mobile rack's connectors. A simple pull of the tray's lever is all that is necessary.

Because of this rack's ON-OFF power button switch there's no need for a keylock mechanism that's found on virtually every other mobile rack. Personally, I've always found those keylocks to be a decided annoyance in the day-to-day operation of a PC.

The rack contains a small fan that is dead silent in operation.

I've never encountered a single problem with the mobile rack's solid plastic construction. It's a sturdy piece of equipment in my experience. As far as I'm concerned its light weight is a decided plus.

Cons: Unfortunately this mobile rack is designed to only house a 3 1/2" hard drive in its removable tray. Four screws are provided to secure the hard drive in the tray (although truth to tell since we frequently switch HDDs we rarely ever use any of these screws and simply slip the HDD in the tray unsecured - connects perfectly to the rack's SATA power/data connectors).

As indicated, the mobile rack is not designed to house a SSD (2 1/2"). Like many users we've been continually switching over to SSDs and pretty much phasing out our 3 1/2" HDDs. We've been able to install our SSDs in the removable trays by using hard foam inserts (the kind of foam usually found in packaging materials) and so far they've worked pretty well. Heavy-duty packaging tape is another option.

We've also drilled two small holes in the base of the removable tray, lining them up with the front screw holes of an SSD so as to secure the SSD to the removable tray. (The placement of these SSD screw holes is standard for both 7mm & 9mm SSDs). But of course it would be so much more desirable for the device to be designed so that it could accommodate both 2 1/2" & 3 1/2" drives. Judging from the current design of the removable tray it would appear that a relatively simple manufacturing modification of the tray would allow the installation of either size drive.
We've been pleading the device's distributor/manufacturer to incorporate this simple modification, but, alas, as of yet to no avail.

After you boot to Win 10 with the Win 7 HDD installed as a secondary HDD in the system, access Disk Management and (as I previously explained) right-click on the Win 7 schematic so that the sub-menu will open. Click on the option "Mark Partition as Active". (I'm assuming the Win 7 partition did not indicate it was Active).
Reboot to the Win 7 installation. When you later want to boot to the Win 10 installation you have to perform that same process for that HDD.