Re: salvage Ubuntu from W7 recovery
Looks like you're asking how to fix the Win7 problems but save off Ubuntu in the process, right?
To save off Ubuntu, I would download a burn a CD of Conezilla, boot from that (with an external drive connected) and use Clonezilla to image Ubuntu off to an external drive. Using Clonezilla is a bit tricky because , unlike other image/restore apps, you have to enter the destination FIRST.
Do you have any kind of Win7 CD that came with the Acer? If so, then boot from that and look for an option to Repair Win7. If you have that option, run it three times -- that's right, three times -- and see if that fixes the Win7 boot.
IF you don't have such a CD, then try using Boot-repair: https://help.ubuntu.com/community/Boot-Repair
If neither of these work, it's possible more got damaged in Win7 than the boot loader filesw. If you have full install media (win7 DVD, not CD), you should then visit the Windows 7 forums (sevenforums.com) and read through their tutorial on how to do a repair install -- which will leave your apps, settings, and data intact.
Ubuntu 15.04 Mate, Mint 17.1; MS Win 8.1, Win10 TP.
Will not respond to PM requests for support -- use the forums.