Slow and Crashes when rendering

When I try to render an image Blender always gets laggy and my internet slows down and some of my other Blender projects open crash. Is there any way I can make it less have lag?

Hi, not to much information, missing OS, System specs, render engine, CPU or GPU and so forth.
I guess you render on Cycles GPU?
Lag is normal, Cycles GPU need all resources of your GPU, nothing left for the system.
The only way out is a second GPU, can be integrated Intel HD for example.

Cheers, mib

its not your internet that slows down.
When you render an image your CPU or GPU is almost 100 utilized.
That causes even the best systems to lag.
So If you want to watch a film, youtube videos etc while rendering you better render with CPU.
Causes less lag in my case.