In the Windows boot-loader, you press F8 and it gives you options like safe mode (unless Windows 8 doesn't have that anymore). In the same menu you press Esc and it gives you the option to go into the Ubuntu boot-loader which is grub. Once you select the option press Enter and you will be in grub. In grub, select Ubuntu and Ubuntu will boot. Once there, go to Ubintu Software Center and install the program "Grub Customizer" (trust me it's a very good program worth installing). Then load the program after installing it, and it will scan all your operating systems. Configure the names of your OS's, and the General Settings. After you are done configuring, click "Save" and reboot. Once your computer down-booted, press DEL or F2 to enter BIOS and make the Ubuntu hard-drive primary boot so that it loads grub and if you want Windows in Primary boot just set as primary in Grub-customizer but still set Ubuntu as primary (if you have them on 2 different harddrives). Comment any questions, and ill help, I'll be on this site a while because I have a big problem with Ubuntu as well. Best of luck!