Be sure that the "makepcid" and "iRacing.lic" are saved at the root of the C drive:
Right click on the Windows Start icon (at the lower left of your screen) and select "Search"
Type: CMD and then press the Enter key on your keyboard
Then type in cd.. (then ENTER) until you see C:\
Then type: makepcid -view (then click ENTER)
Check to see the license is not expired and that the license is valid: