I got this error lots and lots. I still get it periodically especially when a program sneaks into my startup list and does automatic updates...
Basically what it is, is a program is trying to access the internet and connect to server usually for updates (antivirus, etc) and of course an issue occurs and it bombs out.
I don't know why the minimize triggers the issue, perhaps the pc thinks this is a good time to update program xyz and then when you maximize it goes funky.
You can do a few things... or at least this is what helped me.
If you are able to get into task manager ctrl+alt+del (I know it isn't always the case) then go into processes and select the 'Server Busy' program, right-click and select 'Go to Process'. This should tell you what program is causing the error. Either edit or uninstall the program. You can also select "server busy" and end process - saves you a reboot.
I eventually untick any unecessary programs from running on startup. CCleaner has a little section for this. I just slowly disabled them one by one, leaving only those I required / needed.
Use Alt+Tab to cycle through open windows - It helps, and makes you're pc function like a mac (just kidding).