Maybe it was the search terms that I used, but this one was really hard to find.
My system is all UEFI mode, and after several reboots from a bootable UEFI devices, the list kept growing and duplicate UEFI entries were created. This happened both on my Lenovo Thinkpad x230t tablet and also my Asus motherboard (P8H77-I) / SandiBridge Core-i7 desktop.
Solution is really too simple.
Boot up into Windows 7, then open up a command prompt with Admin rights. Type in the following command.
"bcdedit /enum firmware"
You'll be able to see the duplicate entries here. Copy the long line that has {.........................} in it. Then type this command.
"bcdedit /remove {..........................}"
You can type "bcdedit /enum firmware" again to make sure they are gone.
You are all set!
An alternative (brute force) way is to re-flash the bios and restore to default values, but that's probably not a good idea now that you know how to fix this.
