12 processors? That must have been a very expensive computer...with 12 i7 processors in it
1 processor with 12 threads is more likely what you bought, all those years ago. I still work/surf/watch movies (1080p/x265 HEVC encoded) without any problem on an almost 10 year old 2.6GHz Intel Core 2 Duo processor, practically without any problem (sometimes a minor stutter occurs and that is fixed by restarting the WMI service).
You would think that with the shitty power grid here in Paraguay my computer would have died a long time ago or that I was fed up with it. But it keeps working just fine and after adding a SSD hard disk to it, it works great. With that in mind, you hardly need to think about getting a new computer if your usage pattern is similar to mine. But if have not done so already, add an SSD hard disk and boot from that disk. Your i7 will perform better than new.
But ok, say you do buy a new PC from Puget. While Windows 7 will work just fine on any model of new processor (from Intel or AMD) you will notice very quickly that Microsoft will make your Windows 7 installation obsolete. That is, when updating Windows with (future) MS patches, you will get a message saying that your Windows 7 installation won't receive any patch anymore because it runs on a too modern processor.
So, you will end up with Windows 10. Maybe it takes 2 or 3 months after you purchased your new system, but by then the lack of MS patches will make you install Windows 10.
The AMD Ryzen 1700 series processor will beat the performance of your current setup easily and it costs much less than an equivalent Intel processor. The several 100s of USD that you save, can then be used to buy/upgrade Windows 10 Enterprise edition if possible. And if that is not possible, go for the Pro edition of Windows 10. Don't accept anything less, if you work with custom software on which you depend for your income.
All lesser forms of Windows 10 will be updated when Microsoft deems it necessary. You have virtually no control over this and your custom software may or may not survive that update. In case it doesn't, tough luck for you. The Pro and Enterprise edition allow you more time to verify if your custom software remains working or gives the makers of your custom software time to fix whatever problem it encounters. Of course, if you don't have such software and/or don't need the new system for your income, then you can go for Windows 10 Home or worse.
Please understand, I think that Windows 10 as an operating system on itself, isn't bad at all. And there are lots of free tools available that curtail the "phoning home" capabilities, if having a sense of privacy is important to you. My only experiences with Windows 10 are with the Enterprise edition and that edition works well for my purposes. But as I tried to explain earlier in this post, the "rolling release" update method that Microsoft imposes on any Windows 10 Home edition (or worse) is unacceptable for my needs.