Once you have the ISO file, you cannot simply copy it to a thumb drive. You must make the drive "bootable." Use Rufus , a free and lightweight utility.
Acer, like most manufacturers, stopped loading hard drives with recovery partitions years ago. However, they did provide a service to order recovery media on DVD. While this service is largely discontinued for Windows 7-era machines, it is worth checking. Windows 7 Acer Download Iso
Using a generic "Windows 7 SP1 ISO" from Microsoft will likely work, but you will face: Once you have the ISO file, you cannot