Hi there, earthdogmom.

Thank you for visiting the QuickBooks Community. I'm happy to provide you the detailed steps on how to set the timeout duration in QuickBooks Desktop so you'll remain logged in and avoid timing out every 15mins.

The login option is not on by default and needs to be set in your login settings or company preferences. Only the Company File's Administrator can enable the option and it applies to all users of the Company File. The Admin chooses how long users can remain logged in with a maximum of 90 days (default is 2 days). That said, I suggest going to the Company section to start changing your login settings.

Here's how: 

1. Go to the Company located at the top of the page. 
2. Select Users, then choose to Manage Login Settings. 
3. Hit the General tab on the left side. 
4. Under Manage Login Settings, pick the Keep user logged in for and specify the login period.  
5. Hit OK.

Once done, users will be automatically logged out of QuickBooks at the end of the login period you configured under this preference. For more information, check out this article: Stay logged in to QuickBooks company file (sign in without entering your password).

I've included an article that you might use in the future about how to reset your QuickBooks Admin password: Use the Automated Password Reset Tool for QuickBooks Desktop.

Please feel free to get me in the loop if you have any more questions about your QuickBooks account. It's my pleasure to help. Take care!