1. A method of providing graphical indicators of execution progress of commands to perform computer tasks, the method comprising: receiving, at a computer system, a first command to perform a first computer task; comparing the first command to a log relating each of a plurality of commands for corresponding computer tasks previously performed on the computer system or each of the corresponding computer tasks to a measured execution time for the previously performed computer task; retrieving from the log, based on a comparison between the first command and a first stored command of the log, a first execution time corresponding to the first stored command; generating a first estimated execution time for the first command by modifying the retrieved first execution time; and providing, for presentation to a user of the computer system, a graphical indicator of the execution progress of the first command based on the first estimated execution time; receiving, at the computer system, a second command to perform second and third computer tasks; comparing the second and third computer tasks to the log; retrieving from the log, based on comparisons between the second and third computer tasks and second and third stored computer tasks of the log, second and third execution times corresponding respectively to the second and third stored computer tasks; generating a second estimated execution time for the second command by summing the retrieved second and third execution times; and providing, for presentation to a user of the computer system, a second graphical indicator of the execution progress of the second command based on the second estimated execution time.