Windows 8 Lenovo Y500 won't boot / bootloader issue

[Don315]

Hello and thank you to anyone in advance that might be able to help me. The issue started while my younger brother was borrowing the laptop, so I don't have exact details on how it initially started (he claims he didn't do anything out of the ordinary, just happened after a restart). I do have many tools on the laptop though, and though I don't know for sure if he's telling the truth, we all know the damage something iike EasyBCD could do if it's played around with. I hope that's not the case.

So, the point I'm at now...I can get into the BIOS and everything fine, and I see the hard drive listed in the BIOS, but Windows doesn't load. I don't have much experience working with GPT partitions, so I don't think this is something I can fix with my initial idea- bootrec.exe /FixMBR /FixBoot /RebuildBCD. The first 2 completed successfully, but RebuildBCD tells me the system device cannot be accessed. I used diskpart and there is 6 or 7 volumes, one of which is a 260MB volume labeled 'System'. I tried selecting that one and using the bootrec commands but when it said it wasn't a MBR partition, I knew I needed help.

Has anyone else had this problem? How would I go about rebuilding the BCD/boot-sector on this laptop? I can't make many volumes active, because I get either 'System device cannot be accessed' or 'Not a MBR partition'. So I don't know which one to make active nor do I know which commands to run from the recovery environment. Any help would be greatly appreciated. Please let me know if there's any other information needed also.

[allstone]

Have you checked if its set to legacy boot or UEFI boot? Maybe thats what changed. Or what boot error do you get if you cannot boot ?

[Don315]

Other than the USB legacy setting, the only other legacy one I can change is...I forgot the exact name, I'll be home from work in an hour. But it was just which type of drives to boot from first, EFI or legacy. That I tried changing but didn't seem to affect much. I had to set the USB one to Legacy to get it to read my Win8 thumb drive.

[Don315]

I noticed that when I use diskpart on my desktop to see the volumes, the 'System_Res' volume is 100MBs, as opposed to 260MB on my laptop (Lenovo/OEM thing?). Also that it has 'Boot' listed for it in the Info column, whereas the 'System' volume on the laptop does not. Obviously, that lead me to further believe it's a bootsector problem. But with the 'system device is not accessible' and 'partition not a MBR format', I can't get very far repairing it.

Every time I search for a fix, it leads back to bootrec.exe /RebuildBCD or something similar, but I'm pretty sure all of those threads didn't have to deal with GPT volumes, as I don't often see them mentioned. Or if those commands SHOULD be working for me, then I have the wrong volume Active or something like that that's preventing me from fixing it. I'll continue the search for an answer more suited for my hardware/software, but I have no reason to get my hopes up just yet

Edit: Would the bootrec commands not be working because I'm not using a 'UEFI' USB drive for my Windows 8 Recovery Disk? I don't have much experience with GPT, nor fixing these type of booting issues in general. But while searching I found this page- http://www.eightforums.com/tutorials/15458-uefi-bootable-usb-flash-drive-create-windows.html and it got me wondering if maybe that's the problem? I'll give it a go while waiting for a reply, but I doubt that with my luck this will fix everything.