I installed Ubuntu 12.04 on my laptop and it is the only operating system installed. Unfortunately I am unable to get it to boot. After installing it a dialog pops up and asks me to reboot. Afterwards I only see a blinking cursor on a black background.
What did I try so far:
1) Boot order: USB is first, HDD second. When I boot the USB is not connected
2) Holding shift to show GRUB while booting does not work
Help is very much appreciated.
Update on Danatela's comment
I followed instructions found here: My computer boots to a black screen, what options do I have to fix it?
1) The hash of the iso file is correct.
2) Verifying the CD/DVD Integrity (It's a bootable USB drive) -- The output is: "Check finished: errors found in 1 file!" I tried with two different USB sticks and they both show the same error.
I wonder why the md5 checksum is correct but one file contains an error.