Need assistance with searching cells

Good Afternoon,
What I need help with is kind confusing.
Say in Sheet 1, I have a list of computers in Column A. (Computer 1, Computer 2, Computer 3, Computer 4, Computer 5)(An inventory basically)

Now in Sheet 2, I have the users in Column A and Column B through F shows what computers they have logged onto.
The sheet 1 is a common list of computers but there are users that can use computers that are not on Sheet 1. My goal is to track those unknown systems.

Therefore, if say User1, is using Computer 1, Computer 2, Computer 8, Computer 9.

I need a formula to be able to look at Column 1 at User1, look at the computers in columns B through F. Verify which ones are NOT on Sheet 1 (inventory), (In our example Computer 8, Computer 9)
Then give me an output lets say on Sheet 3 saying:

Col A1: User 1
Col B1: Computer 8
Col C1: Computer 9

Then for the next user that shows up with different computers would go to the next row
Col A1: User 2
so forth?

I've attached an example file.
Thank you very much in advance.