Okay, thanks for everything, but i just can't find what causes problem. One last question: Do you think task - RegIdleBackup (in taskscheduler) can cause this?

ESET NOD 2 probably can't do this, as it's only app besides firefox that is open now. Maybe something in task scheduler......

You are very helpful, thanks! Do you know any way I could find what's causing those changes? :)

I checked process explorer and there's no process that could cause such behavior. Maybe win10 automatically "fixes" changes made to certain parts of registry?

No, i didn't even rebooted my pc.

Wow, that was quick :D. Thanks! If it's not too hard, could you do same to "Send To"? It reappears after some time....

EDIT: Both "Pin To Start" & "Send To" reappears after ~3 hours......

Thanks for help anyways :)

folders, exe files, .lnk files in explorer.

I created backup ofc. Put "-" in front of keys. Still "Pin To Start" isn't gone......

Found:
HKEY_CLASSES_ROOT\AllFilesystemObjects\shellex\ContextMenuHandlers\{a2a9545d-a0c2-42b4-9708-a0b2badd77c8}...

Reg key - "[-HKEY_CLASSES_ROOT\*\shellex\ContextMenuHandlers\{a2a9545d-a0c2-42b4-9708-a0b2badd77c8}]" is deleted, but "Pin To Start" still apears in context menu. Maybe there is another key in win10?

Maybe shellmenuview & shellexview? Do you know locations of those entries in win10 registry? I would try delete them by hand....

Thanks for reply, Send To removes using reg file, but returns after PC reboot, Pin to start isn't removed.....

Anyone knows why when i remove "Send To" & "Pin To Start" context menu entries from registry, windows automatically creates new one's after restart. Never had such problem in 8, and it's driving me...