Sims 3 crashing

Just the Windows key will bring up the desktop.

And control, alt, delete will give an option to open the Task Manager where you can force Sims to close with "End Task", then click the little arrow on the right of the task bar

where the EA App will probably still be, and right click on that and choose Exit.

Then open your Sims 3 folder and delete the excess files, like the cache one's, the error one's and there's some folders that can go - I do the Current Game, Content Patch, Custom Music and Featured Items, sometimes Thumbnails as well. 

Then go into Disk Cleanup, 

operate it

or not ... I do.

Then restart the game! yay!

I have used to the Sign Out option, but needing to leave another program open just to prevent complete closing is a bit annoying. I've been using the advice of playing the game in windowed mode (I'd actually forgotten that was an option). If it does crash again I'll let you know if it works out better.

I have used the Sign Out option before when my game crashed. Of course, if you have other documents open (such as Notepad, Word, or Excel) that you haven't saved, a message will appear asking if you are sure you want to continue.

At that point, click cancel. It will take you back to Windows, and your game will be closed; however, all your unsaved documents will remain open. I think at that point it has already closed your browsers and the file explorer.

Go into The Sims 3 folder and delete your cache files before starting your game. I usually delete the script error messages at the same time.

Zophor​  If you click ctrl-alt-delete, can you choose Sign Out?  That would boot you to the Windows login screen and close the game in the process.

If that doesn't work, and you're playing in fullscreen mode, consider using windowed mode instead.  If you don't like the look, borderless mode works like windowed mode but looks like fullscreen.  The Smooth Patch from Lazy Duchess has a Borderless option, and Windowed Borderless Gaming is a free third-party tool that works well with Sims 3.  Either option should be fine.