We're getting a bit of topic here, but if you can't install and you can't restore, you could try booting into Single User Mode:
Hold down Command and S keys at bootup for 10 secs or so. Wait until the command-line prompt appears (after all the text is done scrolling past.) Then type fsck -fy and press Return. Eventually, after five different checks that take varying amounts of time, you should get to one of two messages: "The volume [your Mac's name] appears to be OK" or "FILE SYSTEM WAS MODIFIED." If you encounter the first message, type reboot and press Return. If you see the latter message, though, you'll want to run fsck -fy all over again. You can retype the command and hit Return, or press the Up arrow once and then press Return.
If that doesn't work you can also erase your El Capitan partition in SUM and try again.
Finally, if all else fails, you can restore to your original OS X with Internet Revovery mode:
Boot to the Internet Recovery HD:
Restart the computer and after the chime press and hold down the COMMAND-OPTION- R keys until a globe appears on the screen. Wait patiently - 15-20 minutes - until the Recovery main menu appears.
Partition and Format the hard drive:
1 Select Disk Utility from the main menu and click on the Continue button.
2 After DU loads select your newly installed hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Click on the Partition tab in the DU main window.
3 Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed. Quit DU and return to the main menu.
Reinstall OS X: Select Reinstall OS X and click on the Install button. Be sure to select the correct drive to use if you have more than one.