Can't get Mac OS X Yosemite to download on old iMac
Looking to recycle wife's old 2007 iMac. After following instructions to erase Macintosh HD via OS X Utilities, tried to then re-download OS X Yosemite via Utilities option. Download seems to occur successfully, but then right at the end of the download screen, instead of moving into OS setup options, it goes right back to the Utilities screen and nothing changes. Have tried to download the OS via the internet using Option-Command-R at startup but this does not work and spinning globe screen never appears. It just starts up and goes back to Utilities screen. Stuck at a dead end and haven't found anything here or elsewhere online that addresses the specific roadblock I am at. Should I just give in and recycle the Mac, knowing that I have already successfully wiped the hard drive?
iMac