Setup vs. Set up

The word "setup" comes up a lot in software blogs. Many writers misuse it. Two common cases arise:

Noun

Setup (one word)
"When you've finished the setup script, continue by...."
"The setup process is relatively simple...."

Verb

Set up (two words)
"This is a walkthrough with all steps you need to set up a resource..."
"If you're having trouble setting up the system...."
"This should allow you to set up the...."
"Then the user can set up his own...."
"One can set up a new product by...."

If you're a blogger, distinguish yourself by using the proper case.