I would like to set the windows boot manager as the default boot manager instead of grub, could someone please help me out? I've been on google for a while and all i can find are instructions for setting windows as the default OS to boot to. Ive tried using easybcd on the windows side but doesn't work.
Install the boot-repair program, See this link on how to install boot-repair and follow the following steps.
Select the "Advanced options" in the bottom
Now select on the "GRUB Location" tab
Now change the "OS to boot by default" field to Windows.
Hope this will fix the problem on a restart. Kudos :)
Use efibootmanager to change to boot order
Too keep things simple, you should try to Change boot order using efibootmgr. Just run
sudo efibootmgr -v and look for the line that says
Windows Boot Manager. Please add the output of the command in your question to be safe.
Here is the key quote from Rod's answer:
sudo efibootmgr -o 0,1,2
This command will set the two ubuntu instances first, followed by the Windows Boot Manager entry.
In this example with this explanation you would want to run
sudo efibootmgr -o 2,0 to set Windows as the default.
The background is, that this depends on a properly working UEFI setup with a standard compliant firmware. Since you write that you run Windows 8.1 without a particular model number of the computer you are using or any modifications that you made and you haven't experienced any issues I have to assume that this is the case.
Note that Windows doesn't detect other operating systems by default and I don't recommend changing the BCD configuration by hand or with 3rd party utilities. This is exactly what you asked for and you would need explicitly choose Ubuntu during the boot process, which can be very annoying too.
I recommend looking at the answer from keepitsimpleengineer which has been suggested in the comments. It works independently from UEFI or BIOS and is the most convenient solution I can think of. From my point of view it's standard functionality within GRUB and doesn't require any 3rd party utilities.