SSMS takes a long time to open up connection for each new query window

Issue:

SSMS takes a long time to open up connection for each new query window. This applies to all other applications that connects to the database as well.

Fix:

Disable The Publisher Certificate Check

Part of the SSMS start-up routine involves connecting to the Microsoft website to check a certificate list.

You can disable this with these steps:

1. Type “Internet Options” into the search bar to open the Control Panel window
2. Click on the Advanced tab (top far right)
3. Move down to the Security section
4. Uncheck the option called “Check for publisher’s certificate”

Disadvantage

This makes your computer less secure. Try all the preceding tips before this one.

Sources:

How To Fix Slow Start-Up Of SQL Server Management Studio (7 Ways)