I have just partitioned my relatively new Asus K55V Windows 7 machine with Ubuntu 12.04. I installed it from a memory stick as usual, following precisely the instructions on the Ubuntu website. I chose the size of the new partition, set up my account, installed Ubuntu - all seemed normal. I then restarted the system and immediately after 'ASUS' pops up before the machine boots up any operating system the message 'error: efidisk read error.' appears three times, and is followed by the grub menu offering the option of loading Ubuntu or Windows 7.
That seemed all right, although I was puzzled by the errors; I went into the Ubuntu system, though, and all was good. Then I went to go back into Windows and, rather than loading up, the message 'error: invalid EFI file path. Press any key to continue...' appeared.
Pressing any key returns me to the grub menu and Windows just will not load, what exactly is going on and how can I fix it? It is vital that I get Windows back since I use Windows regularly as well as Ubuntu.
Any help would be very very much appreciated!