TWRP not seeing rom ZIP files on my ancient HTC One M7 -- help me upgrade?

[Android Central Question]

I'll try to be brief, although I've spent many hours on this today. I got in on the Sprint BYOD free year or service promo today using an old HTC One M7 (obviously Sprint version) I had in a drawer. My primary goal was to upgrade it to Android 5.0 or higher so I can put Android Auto on it and leave it connected to the USB port in my car. Right now it's got an old Bad Boyz 4.1.2 rom on it. Anyway, I downloaded a couple rom zips from XDA, but for some reason TWRP wasn't finding them in my storage (The M7 storage is called "sdcard" even though there's no removable storage. TWRP was seeing some old roms I had in there from forever ago, but not the new ones. I then noticed one of the new roms required a higher version of TWRP for a proper install, so I used Flashify to install 3.2, but the zip files still weren't showing up. I used Flashify again to downgrade to 3.0, but still no dice. The zips show up in various file managers once I boot the phone, adn I can move them around/copy to different folders. But as soon as I boot into recovery, TWRP doesn't display them. I've tried going into "Mount" and checking/unchecking "System Storage." I've also tried sideloading, but my Windows 10 computers aren't talking nicely to the phone via adb. Any help getting a newer version of Android on this old beaut would be appreciated!

 

[Rukbat]

1. Install the HTC Drivers so your PC can talk to the phone.

2. If TWRP is seeing .zip files, it's seeing .zip files. ROMS you download aren't TWRP backups, so don't look for them in Restore, look in Install. (And make sure they're located in a folder you can get to, like /sdcard.)