Certainly the breakdown in influence for say your standard PC will be hard to avoid any USA input, no matter the OS due to code submissions/contributions and then that's presuming honest location actors. Let alone binary blobs for drivers.
So hardware and OS, you will be pushed to avoid any USA influence.
After all USB, Intel did that, clearly USA influence, as are many standards, so I dare say that unless you build your own CPU and everything, you will be having some USA influence upon your system, one way or another. Let alone many other countries.
Heck even all those 6502/Z80 systems - USA companies invented those, so not even the humble Sinclair ZX81 would still have USA in there.
Though I'm sure that Russia and China do have computers without any USA in them. But then, you start to see how that works.
Gets down to trust, which for some can be a choice of sandwiches they don't like but they need to eat. Most like the sandwiches, some like all three flavours and some make their own flavours, but using ingredients from all three. Some will bake their own bread and use the standard ingredients. Very few will make their own flour, bread, ingredients all by themselve. Coz they still use an over and knife made by somebody else. See, the efforts to exclude any potential influence is so deep that to completely remove them all is beyond the scope of many. So gets down to a balance, a trade off of trust.