Trusty now comes with the capability of restoring broken systems. If all else fails (Grub Rescue .. etc.. ) then you can use the TT.iso.
When booting up you can choose re-install or go to <something_else> during the partitioning session of Ubiquity. Choose sda(n), (where 'n' equals the partition to be restored) then, Change. Make partition ext4, choose '/' (root) but do not format. It will save all fo your home files and bookmarks but you will have to reinstall some programs. Grub Rescue has always worked for me when installing an Ubuntu Product side by side with a Windows product. Especially Windows 8 and UEFI.