El Capitan not installing after first restart I have successfully downloaded and opened the program to install El Capitan on my computer. However, after the computer restarts the first time, it boots back into Yosemite and it doesn't continue.

When it reboots Yosemite works, but nothing seems to have changed.

I have run the installer 4+ times now and I haven't been successful.
If the El Capitan install fails for any reason, it automatically rolls back to Yosemite.

Could be many reasons for it not to work like HDD issues, Install file corruption or space issues?
Also, Is it an older El Capitan installer? Downloaded a while ago? Apple's certificate expired a while back and it could be failing for that reason. Try downloading it again.