Doing some google searching, I learned that with older computers, these latest Flash Drives may not be listed in Device Manager and may require a driver, but no clue where to get that. Has some words in list like USB Root Hub, one of them for my mouse I think, and I should probably go back to open the others while I'm waiting, but had already read something to the effect that Flash Drives may not work with older computers.
At least without a special driver. Probably it installs just like HP Drivers, but I for one never heard of PNY, bought it at Staples.