It is usually not a good idea to reset the ECU without first figuring out what is wrong. See "How can I find out what the "Check Engine" light means?", above. In many cases, resetting the ECU will increase the learn time, not decrease it.
For instructions on resetting the ECU and what this can accomplish, read this issue of The Diagnostic Port, and this section of the ECU Theory Series, both by Technomotive