Use the [Search] feature (just above the Calendar to the right), and search for "friction".

I always recommend:

• a case without friction
• a case with the most reasonable low value of friction (mu)
• a case with the most probable value of friction (mu)
• a case with the most reasonable high value of friction (mu)

Then use the Load Case Option MAX to give you a summary of these conditions - which will give you the worst situation.

Remember, friction can only be used to hurt you, never help you.