[Inori]

Windows really shows it's BIOS-hogging, system-monopolizing self on a boot level, because if you've installed a grub-supported linux distro alongside Windows, your default UEFI boot settings will automatically start Windows when you boot.

To fix this, restart your computer and press f12 on the startup screen (always the first thing you see, has your computer's logo with a blue loading bar), navigate to your boot settings, and change your boot mode to legacy.

Now, whenever you start your system, grub will start before windows. To start windows instead, hit f12 on the startup screen and select HDD-1 (the option will have your windows version as well as HDD-1).

[Nil]

Also be aware that while F12 is usually the correct button for most computers, it may differ on yours. I know for mine (asus) I use F8 I believe, will have to double check. And sometimes ESC works which will pause the startup and let you choose from there.

While you're in the EUFI settings you may also have an option (possibly under save and exit) that lets you manually boot the usb drive, which should work without changing something.

If you're still having trouble, you could possibly need to disable secure boot.

[Satan]

For a while I just used OSL2000 instead of doing all this, but useful guide.

[Yung Lean]

Well on mine dual boot I get a window to choose which operating system I want to boot.

[Inori]

Well on mine dual boot I get a window to choose which operating system I want to boot.

From what I gather, grub takes priority on anything <windows 8.1, so this is more for troubleshooting with newer versions

[mothered]

If you're still having trouble, you could possibly need to disable secure boot.

Exactly this.

Whilst It does serve It's purpose rather well (prevent unauthorized OSes from booting etc), I find Secure Boot to be more of a pain than anything else- particularly when Installing pirated copies of the Windows platform.
Thanks for the tut Nevermore.