I've always been a reclaimer. From my early youthful days of dumpster diving at the phone company for wire and occasional batteries and salvaging old TV sets to build gear with the parts, I've thought why let useable hardware go to waste or worse: a landfill. I recently found a good, clean Intel i7, 4th gen CPU workstation for a reasonable price, but without its hard drive. It did have the OEM Win 7 Pro software key, so I thought why not put in a new hard drive and restore its OS and then upgrade, if that were still possible. The good news, thankfully, is.... it still is possible to do it with permission of Microsoft. But, not with cogent instructions, since I guess they'd rather you pay for a new set of Windows 1o software. Their "easy" upgrade offer went away about 5 years ago. I'll try to explain how I did it, finishing today, on my new-to-me desktop tower PC. I did one of these upgrades a couple of years ago, and since then, Microsoft has changed the steps needed to make a free, no cost upgrade. I decided to reinstall Windows 7 pro, 64-bit version since the machine came with 16MB of RAM. Unless you have an OEM software disc, you will need a “Windows 7 Reinstallation” disc. I bought one several years ago for less than $10 on eBay. When you run it, it will ask you what version that you want to install. I wanted to have a 64-bit OS, so I chose Win 7 pro 64-bit. I then spent about two days (a long time) installing the needed hardware drivers, especially the network card for web access. I then updated Win 7 as far as I could, since it has to be updated to well beyond SP1. CNET and some other sites talk about downloading the Microsoft Media Installation Tool and leave you with the impression that’s all you have to do. Nope. That used to be the case, just simply run the software. Things have changed. Instead of it allowing you to go beyond the page that asks for a Windows 10 key after running, it simply stops right there. No other options offered, other than to exit the tool. The free upgrade is now more complicated. You have to establish an Administrator account under Windows 7 and log on as Administrator. You can do that as follows: Press Control-Shift-Enter. That should open a command prompt CMD window. Then type “net user administrator /active:yes” You should get a message “command accepted.” Now, logoff and reboot. You should see two user icons. Click on the Administrator icon. Go to the MS Media Download Installation Tool site (I’ll leave that detective work up to you) and down load the application file. Run it and check “upgrade this PC,” when asked. Let it run as it takes a good 15 minutes or so to get to the end of the installation process. No, it’s not yet installed. You will get an option screen, eventually, offering “automated telephone activation.” Check that box, then dial the number on the screen. The computerized lady will give you some activation digits to enter. After you enter them successfully, she will congratulate you on activation. However, it’s still not installed. Next, close the screen and quit the Media Tool. Now, restart the Media Tool, again checking “Upgrade this PC.” This time, instead of it hesitating and asking for a Windows 10 key, it will proceed to install Windows 10. Good luck and 73. You should now be able to run the latest Win 10 versions of SDRs, soundcard modems, etc.