Yesterday I went over to my brother's flat to install the SSD (256GB 850 Evo) and HDD (2TB Toshiba) he bought and get Windows 7 Pro installed on it. It turned out to be a complete hassle, because:
1. His friend gave him his old Windows 7 key (not strictly ok, I know), it was an OEM copy of Windows 7 Pro that would also activate Windows 8.1 and 10, but only the Pro versions. The Windows 7 key he already had was for Windows 7 Ultimate, so he could only use the Windows update tool to get Windows 10 Ultimate (or something, not the Pro version anyway) so when the update tool asked for a key, it wouldn't let him activate it.
2. Microsoft don't host the free ISOs of old Windows versions that they used to and the only mirror I could find dealt only in torrents - neither of us know anything about torrents. Fortunately we're not stupid and it's not difficult so I was able to get the Windows 7 Pro ISO, I also checksummed it and it was a legitimate copy.
3. Then, after making the installation media, the installer asked me for the DVD/CD driver even though it was on a flash drive. After much head scratching I realised it was because it was in a USB 3.0 port, so I put it in a 2.0 port and it was fine... Except:
4. I'd formatted both of his new drives as GPT rather than MBR, and Windows 7 didn't want to be installed on GPT. Instead of giving me the option to revert the drive to fresh-out-of-the-box spec I had to boot back into his old install and use DISKPART to fix it (which, again, was easy).
5. It still refused to install but didn't tell me why, but I Googled the error code and the solution was to remove all of the other drives from the PC.
After that it worked fine, all I had to do afterwards was download the drivers for the motherboard and graphics card, set up Chrome, Steam and Nvidia Share for him and I was on my way... A mere three hours later than I'd anticipated.
Next week, barring any unexpected expenses, I'll hopefully be buying some DDR4 RAM to motivate me to save for the CPU and motherboard to suit it at the end of March. I was thinking 2x8GB DDR4-3200, probably G.Skill because I've had a total of 24GB (6x4GB) of G.Skill DDR3-1600 since 2011 and it has been flawless so far. The CPU and motherboard are obviously going to be an i7-7700k (with a Noctua NH-U14S) and an Asus Strix Z270G, replacing an i5-4690k (NH-U9S) and Asus Z97-M Plus, which will be rehomed in a Silverstone GD-05 (USB 3.0) HTPC case as a second PC that I'll probably sell to a friend... The money from that will go toward a 27" 4K monitor. I've got my upgrades planned.