Don, there are a lot of choices, and a lot of "What are YOU willing to do?" options.
I personally still keep older PCs running XP because Nero 6 & 7 have a great, easy video-editing tool. They stripped this off in the last Win7 versions, so fine, XP boxes stay, doing what they do.
Hauppage 1600+ (1800s, 2200s) TV-cards, those have hardware MPG encoders. This supposedly reduces CPU usage, so an older CPU is just fine. But those are the more expensive cards ($70-120). They do produce an excellent video-quality 'capture' of a TV broadcast.
There's also a storage-issue. We have a PC-as-DVR unit (the older WinXP box), and a separate media-server (Win7-64) because it offers the huge 3-4Tb HDD storage capabilities. We tend to record on one PC and do the broadcast-edits (usually old movies from TCM, the ones that will never make DVD-BluRay releases), and then shuffle those off to the media-server for 'watching' and storage.
If we had to replace the XP box with a newer board & processor - newer, faster, etc - then ASROCK still offers good motherboards with floppy-drive connectors for an easy XP installation, still using the hottest new processors, though. (Otherwise, we'd have to slipstream in an XP CD with SATA drivers for ASUS, Gigab, etc.)
There is another useful debate going on about How Best To Use SSDs, and "reliability" is my concern. By getting two smaller units (40-60Gb?) I can clone off a fully-loaded C: Drive and be quickly back in business if I suffered a Rootkit attack, or an SSD death. And fairly economically, too.
This would be useful, also, to enforce a discipline to put all data onto a Data-Drive HDD. If the SSD died, then fine, no data, no recordings are lost. If it never does, then I've wasted $50-60 on an identical duplicate SSD. One year, I'll use that for Win10-SP3 or whatever.
So... am I willing to do Video Edits? (Chopping off Beginning & Ends of TV recordings? Am I willing to do Chapter Marks? Do I need or want to do Menus?)
Do I want to consider using an Old PC with a good TV recording card for that then?
Do I want to consider a newer box for bigger media-file storage?