GRUB 2 provides excellent capabilities for troubleshooting and correcting boot problems from the boot menu or GRUB 2 terminal.
The ability to manually boot using the Grub command-line constitutes the biggest security risk in Linux.
Any OS can be booted in this manner from any USB or CD/DVD drive, circumventing BIOS restrictions.
It can also limit access to specific entries for specific users, and can encrypt plain-text passwords for increased security.
Please refer to the Grub2/Passwords community documentation.
Finally restart and switch to Windows, adjust system clock time if need and done. Make Micro Soft Windows uses UTC: Another way to fix this issue is doing the following changes in Windows, Windows 10, in the case below: 1.) First if you’ve switched to local time in Ubuntu, run command in Ubuntu terminal to use back UTC: I'm a freelance blogger who started using Ubuntu 5 years ago and wishes to share my experiences and some useful tips with Ubuntu beginners and lovers.
Please notify me if you find any typo/grammar/language mistakes. It says (edited): Many users are reporting that some of their partitions disappeared after installing the Anniversary Update.Usually, it's the smallest partition that disappears, although we couldn't say for sure whether the partition is deleted or if Windows simply doesn't detect it.For users who dual boot Ubuntu 16.04 and Windows, you may find the clock time is off that causes time differences after you reboot and switch between the two systems. Ubuntu maintains the hardware clock (RTC, real time clock) in universal time (UTC) by default while Windows maintains the clock in local time, thus causing time conflicts between Ubuntu and Windows.To fix it, either set Ubuntu to maintain RTC in local time or make Windows uses UTC. Disable UTC and use Local Time in Ubuntu: In previous Ubuntu editions, you can edit the config file you’ll the local time zone is in use in the Warning section.GRUB 2 is a descendant of GRUB (GRand Unified Bootloader). Grub version 1.99 became the default on Ubuntu 11.04 (Natty Narwhal) and introduced some major changes in the Grub file contents.