Protean

As far as I understand the LM quirks and features it depends a lot on its possibility to melt into metal plates to be considered as one. I also heard about some LM manufacturer that added some sand paper to scratch the surface of connecting layers

Copy these files by using some pendrive, cloud storage or sth if you don't want to unplug HDD

Your apps originally were installed with some installer (the fancy window app where you click "Next" "Next" "Agree" "Finish" etc.) These installers usually put some stuff into windows registry that may be important for seamless work and this is what you cannot copy-paste between disk like files. You may try to copypaste the files, but more likely something will crash during app launch or during work. Right now I think its best for you to try to copypaste these files between drives. Eventually it will just work

OEMs are cheapter because OEMs are mostly for offices. Let's say you have a company that runs 80 PC in its headquarters, and if one of these PC go broken they you either send it to its manufacturer (warranty) or leave it to rust in a corner (since these are like 100-200USD machines not worthy to fix) Having 80 cheap PCs requires you to have 80 Windows licences, there comes an OEM where you can buy a W10 for ie. 50USD instead of 200USD, but you can run it only on one registered coniguration. For me as an individual who is going to upgrade some RAM over time, change a notebook etc. I go for Retail for my own sake. So Retail works on my PC1, PC2, PC3... I think the limit is up to like N-registrations of different hardware configs. There is one detail in all of that - only 1 retail licence key can be used at a time. You cannot use a retail key on 100 PCs at one time. Also watch this:

Dunno, I ve never had an OEM. You should ask somebody who had OEM OS, especially W7 since its extended support expired.

Ad 1. A opposite version of OEM is Retail, but nobody cares that much unless they need to. On everyday basis its just a "W10" or "W7" Ad 2. Letter assign is not enforced, I believe it may change if you connect another disk, but yeah you are right about the rest. However you may not be able to run W7 apps on W10 OS (it may work, or may not). Ad 3. No, not really. You cannot just copy-paste Windows directory to another machine and expect it to work. You would need to create additional partition on that bigger disk. Since I suppose you have only 1 partition on that big disk then you would have to shrink existing one to make a "Free Space" for new one. This itself can be done with more or less sophisticated software that will warn you about the risk of loosing existing data. After shrinking the main parition and making a new one you would need to install Windows 10 there. After installation of W10 you may need to add W7 in bootloader (if W10 ignores it presence) with app like EasyBCD, and after all of that you could move files form backup. At this stage I would highly consider just using 2 disks, the risk of loosing data compared to HDD value in 2020 is not really worth it.

Your OS is on the disk entirely, you can put both of these disks into COMP 2 since there are always at least 2 sata cable slots on any motherboard. When you mentioned a dude from Microsoft I may think that he mentioned the OEM version of the OS. OEM versions of the OS are bound to the hardware ID, it does not mean that its installed on your motherboard, but it mean that it will run on exactly that hardware configuration. First check if your W7 is an OEM version (google how-to). If it is an OEM then probably you should not put it in other hardware configuration (same principle for W10). My knowledge around OEM revisions is very limited since I never bought an OEM OS.

OS is never installed on motherboard. You will have two disks with their own MBR (master boot record), this is a part of the disk that is related to a bootloader, and a bootloader is a OS selector (if you ever had dual OS on a HDD then you had to make a choice where u want to boot). I expect that your motherboard will boot a OS that is on a first disk in boot order in your BIOS, if you will want to boot into other OS then you would need to press F10-F12 (it depends) to select another disk as the one you want to boot from.

Yeah, it should. Both E6550 and E8400 were working fine with W7. Both CPUs has LGA775 socket... I don't see there any hardware complications

I don't really think that is a truth. I live in Poland (central Europe) and here I bought a notebook that was broken (also it has some private files from previous owner, GDPR were not a thing back then, but they could do a f***ing full disk format instead of quick one). I returned the laptop back to the shop, and they didn't say a thing. I just want to say that if you tell about such things its worth to note where you live - different places have different consumer rights

I was always wondering if this is a case for things like notebooks for 4K USD. Even if you can produce that hardware for 200USD as a manufacturer, it is still expected to give you 3800USD of income. I think that if that hardware could be refurbished under 5 hours then its worth to make it.

Some general rule of thumb: while working with prehistoric software is to just backup the disk anyway. Most of the old software is never going to get a W10 support, nor the activation process will be available all the time (the servers will go down). If software is like really old then it may not work on newer OSes. Expect a lot of troubles with making them work after "installation". If you want to make that working on W10 then go for VM like virtualbox and emulate the older OS if this is something from XP era

I got an info that I can upgrade to newest BIOS but I have to reset it to factory settings to make undervolting work. How to test the system stability in a reliable way? Will cinderbench be enough for that?

I am both a developer and person who loves the freedom of where I can work for living. For gaming I am more into consoles, but for developing stuff I need to make an upgrade from my old Dell Inspiron 5748 (17 inch, i5-4210u 8GB ram GF 840M) that I bough 5 years ago. I cannot say a bad word about this construction tho, no hardware nor physical element has been damaged (except keyboard but I am a gamer so I smash some of these flat buttons hard) since I bought it - a very resistant build I can recommend for some office work (as of 2020). I use a notebook flat desk everyday, and I also repaste it once in a while

While I don't close the screen often (I usually leave it open and don't care), I am more interested where the flaw resides. If this is a breaking plastic fault then it could be fixed with some more expensive brute glue mass, but I think that this is a fault of lacking a loctite on the screws. I may buy a loctite and place it on a hinge screws to make it more secure. I would appreciate some info what exactly is messed up there