This question already has an answer here:
A few days ago, I upgraded my Windows 8 Lenovo U410 ideapad to Windows 8.1, and it proved to be a terrible mistake. It seems like the only visible change that it has made is adding the start button. Meanwhile, it disabled my audio, and I had to go and reinstall drivers from Lenovo's website. Even worse, it is completely blocking me from running Ubuntu in any way possible.
I have my hard disk partitioned into three main partitions: 100GB for Windows (in NTFS); 100GB for Ubuntu (in ext4...I think); and a 550GB storage drive (in NTFS). Then on start up, the Ubuntu GRUB screen (this one) would come up and I would be able to choose between booting into Ubuntu and Windows 8. However, now after the update, I boot straight into Windows 8.1, and cannot access the Ubuntu file system.
This wouldn't be that big of a problem, if it wasn't for the fact that three almost-finished Honors English papers are on there, and I NEED them. So first I tried booting into the Ubuntu partition from the bios, which didn't work, and neither did trying to boot into it from the "Use a Device" menu in the Windows "Advanced Startup" menu. Next, I tried moving the Ubuntu partition to the first spot in the boot sequence, and starting up my computer again. When that had no effect, I created an Ubuntu USB drive, and went through all the same steps (this is what the answers to questions similar to mine recommend). Again, no result. I've also noticed that even after changing the boot sequence in the BIOS, Windows Boot Manager forces itself back to the front.
I'm at a loss for what to do, and I really need those English papers, so any help is MUCH appreciated. Thank you for reading this far, and thanks in advance for any advice.