I had a windows 8 laptop that I actually liked except it typed certain letters twice. So, for instance, I would type the word instance and it would always come up " instancee" Under warranty tech had me reload the file that controlled typing but the problem still existed. I purchased an external Bluetooth keyboard thinking the key itself might be sticking. Problem persisted. Gateway had me update to win 10. Problem still existed.
I purchase a new Toshiba laptop with win 10 installed. Same problem exist with the new computer. Best Buy actually took it back and gave me a new one within 3 days of first purchase. Now Toshiba wants me to box it up and send it in for repair.
If you're wondering; it's not just the letter "e" it happens with other letters as well. But a few letters it happens more than others.
This part will make you scratch you head: I tried typing in tablet mode and it still has the problem. Then I tried dictation and it still doubles the "e" more than any other letter.
I've been living with it but I'm thinking of going Mac