Solved Cannot boot Windows 8 Pro x86 unless I press F12 (network boot)...

...but I can't now because I scheduled a disk check that gets stuck during 27%. D:

How it all began:
My younger brother plays games a lot (he has been experiencing frequent BSOD crashes, too).
According to him, one day it just won't boot (a blank black screen shows up), and he had to press F12 (network boot, and I do not even know what that is but it works).
From there, I scheduled a disk check and thus I rebooted. The progress however, gets stuck at 27% D:
Also, I can't skip the disk check. It doesn't give me a 20-second time to press any key to skip it.

What I tried:
Inserting my installation DVD in my external DVD drive but it won't work. The drive led light blinks and I can hear the drive trying to read it, but I think it can't (DVD drive doesn't show up on boot menu). Works perfectly here on my netbook, though.

Restarting and booting on the HDD, or pressing F12 brings up the Automatic Repair which says it could not load Windows properly and asks me to do a system restore.

More information:
Once I witnessed the blue screen (it's the one with the sad emoticon, right?)
and I remember the words: driver_irql etc., etc...

Help, please?

After 9 hours of wait without getting any reply, I suppose nobody can help me D:
edit:
I finally found the solution.
I'm gonna put my Windows 8 installer on my USB and make it bootable, since my optical drive isn't being recognized by Windows anymore (I've seen many on the net that has this problem, too).

But I still need your help, because I don't know what to do from there. >.<

Did a refresh afterwards, everything works perfectly now.