The number of attempts that will be made to loop through the specified list of installers.
In the event that no installer succeeds during the first pass through the list, this allows the entire list to be attempted again, up to the limit specified. Zero or negative numbers are ignored: If a number less than 1 is specified then the number 1 will be used instead, so the list will always be attempted.
Note that this is cumulative with the "per installer" attempts, so if both are set to 3 then (in the event of repeated failure) an installer may be attempted 9 times.