How to block programs from using internet connection while startup

After starting up windows, it becomes inaccessible for 2 or 3 minutes and got the internet connection icon loading in the taskbar, it may caused by a program that needs internet connection while startup or after startup. So I want to know which program needs internet connection while startup or after startup and how to block it from using internet connection. There may be another cause for this problem, so I need your help

Your post is very generalized, so it's hard to provide useful help with what's stated. Given this, if you comb through the boot up services and identify any 3rd party programs that might use the Internet, jot them down. Once you've done this, modify their entries in services.msc to "auto start delay". That may help you.

If you really don't know where to begin, you can try disabling all start up services, then enable them a few at a time until you start seeing the lag. This should help give you an idea which one(s) is(are) the culprit.