Packages were updating when somehow the power failed (battery fully charged and power got disconnected). Now it won't boot. It doesn't even get as far as GRUB. The bios says it can't boot and press any key to retry. Fortunately all data is backed up and I can boot a live SD. Now what do I do? Model: Dell Latitude D630 Dual-boots with Windows 7, but since GRUB doesn't show up that's not bootable either. Thanks in advance for any help!