This requires you to delete game files. On top of that, its files outside of simply going through steam's [Browse local files..] button. As always, do at your own discretion and be mindful of steam's cloud save system.

also... this guide is intended for people who want to reset the Keyword Database. (ie. those keywords that tell you key details to help you understand what the heck people are talking about) Aside from that, you can ignore past saves and override them when you need to. For some people, they can ignore the Keawords not showing up.

To find the save data, you of coarse need to find it.

The way i was told to find it was...
but i didn't find it there...

I actually found it on the Documents shortcut on my computer (don't ask me what the difference is) so if you don't find it there then try that.

Once you find the My Games folder, mages_steam should be there.

Hold on... stay with me...

Crack open mages_steam and look inside. you should see a folder named STEINS;GATE.

...I wonder if its related to the game?

Jokes aside, inside that should be the save data... looks like this!

Delete the entire STEINS;GATE folder. If you are nervous about doing this...back up this data in a different place.

That should be it!

Open back up STEINS;GATE and see if it worked. The game should start in winded mode if it was previously full screen an a status window in the game should say "creating new game data" or something similar implying the game thinks this is your first time playing. If all your saves are gone and you no longer have the Keywords saved then it's safe to say you did it!

Be mindful that Steam Cloud Saves may come in and ruin things. if you don't want to deal with it, just turn it off in settings.

Show support if this helps!

For proper credit sake, I got the details for this guide from this forum post I made.

I hope i help a lot of people get better enjoyment in this game!