Everything Settings

You either know the pain of redoing your settings every time you get a new alt or worse, have to reinstall Eve, or you would at some point in the future.  No more!  After today you'll never have to redo your setting again.

Export and Import Settings

You can export all your client settings including overview settings, window locations, chat channels, etc. by copying the settings folder in C:\Users\%USER%\AppData\Local\CCP\EVE\c_program_files_(x86)_ccp_eve_tranquility to a safe place.  I recommend zipping the settings folder and mailing it to yourself for easy access if you ever have to freshly install Eve.  If you haven't already done so, you'll have to show hidden files and folders to see the AppData folder.  c_program_files_(x86)_ccp_eve_tranquility might have a slightly different name depending on where your Eve client is installed. If you want to export or import setting to Singularity, look for the folder ending in singularity instead of tranquility.
To import your settings, make sure you've run Eve at least once since you installed, close down Eve, go back to where the settings folder is located and overwrite the settings folder with the backup.

Copy Settings Between Alts

Warning: this is complicated!
You can copy the settings from one character to your others by going to the settings folder (see Export Settings above), make a copy of the core_char_#########.dat with the settings you want and rename the copy after the core_char_#########.dat you want replaced.  To find the correct file, go to https://gate.eveonline.com/Profile/character%20name (use %20 instead of space) and click on the magnifying glass on the portrait.  The file you want will have numbers matching the URL (https://image.eveonline.com/Character/########_1024.jpg).  For example, I wish to replace Lucas Genos' settings with Tikktokk Tokkzikk's.  I go to Lucas Genos' profile (https://gate.eveonline.com/Profile/Lucas%20Genos), click on the magnifying glass on the portrait, write down the numbers from the URL (https://image.eveonline.com/Character/91016881_1024.jpg) and delete core_char_91016881.dat. I then go to Tikktokk Tokkzikk's profile (https://gate.eveonline.com/Profile/tikktokk%20tokkzikk), click on the magnifying glass on the portrait, write down the numbers from the URL (https://image.eveonline.com/Character/90361251_1024.jpg), make a copy of core_char_90361251.dat and rename the copy to core_char_91016881.dat.  Now Lucas Genos has a copy of Tikktokk Tokkzikk's settings.

Always keep your settings backed up!