I want to reboot from Windows 10 into Linux from USB. I am doing it by restart with pressed shift key. But it is very slow. After press restart and shift together I wait more than 1 minute on black screen. No cursor, no disk activity, nothing only waiting. After more than minute I will se standart Windows Boot Manager light blue screen with options to repair, restore and other boot options. Exactly how i expect it.
Boot into normal mode its OK.
When I had Windows 8 it worked fast (under 10 sec), after update to 8.1 it was slower (under 20 sec) but it was acceptable and now when I had cleanly reinstalled to Windows 10 its very slow (more than minute, last attempt take more than 2 minutes).
I suppose that it is caused by NVRAM where are saved informations that Windows Boot Manager uses to advanced boot and there are some useless things that was saved by many Windows installations which i have done. I assume so because computer in black screen time don't use disk and problem was not resolved after clean disk installation (before installing Windows 10 I removed all partitions).
How to make it fast as it was in Windows 8 era? Do you think that my assumption is right?