I have been running Windows 10 on one drive and Mint 18.2 on another drive in my desktop and started having more windows issues so I just removed the windows drive and did a search on how to stop the GNU Grub 2.02 screen from showing during boot since I only run Linux now but all I could accomplish was removing windows from the boot selection list using sudo update-grub but that still leaves the selection screen that goes away after a few seconds and then Linux Mint boots. Is there a easy way to remove the boot selections all together and boot straight into Mint? I have only been using Mint a few months and really enjoy it but I am new and trying to learn this so please forgive me if this is a goofy question. I don't want to format and start over if I don't have to. Thanks

There will be a bunch of guides out there - anything for Ubuntu will be applicable.
Certainly no need to re-install. How comfortable are you using the terminal command line ?. Basically you need to change the timeout in /etc/default/grub and run update-grub. All done.

If I could find a step by step guide to do it by command line I could do it but I couldn't find one specific to Mint. I will search some more. Thanks

I try to run gksudo gedit /etc/default/grub and after my password nothing opens to edit, if I try to use the file manager and open the file I do see

GRUB_DEFAULT=0
#GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

but it is read only so I cant change grub timeout. Any suggestions on what to try

Looks like (in Cinnamon) you can right click on the file in the file manager and select "Open as Administrator". Edit it to zero, and save. Then run update-grub as sudo.

Even though I log into Mint without problems and my password works to update software I get authentication failed if I try to switch to su - and if I manually try to edit I get read only with no option to run as administrator

I got frustrated and did a clean install. Thanks anyway

^ But you didn't learn anything by doing that.

while some distros do not come with sudo preinstalled or configured, others seem to be doing the opposite - they deliberately disable the root account.
in other words, using sudo probably would have helped there.

this was a small, non-critical and simple problem - if you reinstall every time something like this happens...