Give it a try with the Windows 7 Repair CD, then if necessary use the Paragon Rescue CD linked earlier to retrieve your files: System Repair Disc - Create
Boot the Repair CD to see if it finds the installation and then offers a Repair. If not, click through to Recovery Tools list to run Startup Repair repeatedly with reboots.
If this fails after 3 separate attempts with reboots, Choose Command Line in the Recovery Tools list, type:
SELECT DISK # (replace # with the HD # for Windows 7)
SELECT PARTITION # (replace # with partition # for Windows 7 partition judging by size and position)
EXIT (make sure it exits DISKPART)
Now return to Recovery Tools list to run Startup Repair up to 3 separate times with reboots to attempt to Start Windows 7. If this fails, open a Command Line again, type:
Then run Startup Repair again repeatedly to attempt to start Windows 7.
If these attempts fail, you will need to retrieve your data then recover your system using Factory Recovery disks or by running Factory Recovery partition. Acer will send you the disks if you didn't make them; read your manual to learn how to run Factory Recovery partition. Your manual can be read or downloaded at Acer's Support Downloads webpage for your model. You are still under one year Tech Support warranty so I would use it to support these steps, or tap them for other approaches.
Always keep files backed up in future, along with a System Image of Windows 7 so you can reimage HD in 15 minutes with an image you save externally, then replenish your files saved separately.