Reboot

If ISY is online, you can use Admin Console | Configuration | System and click on the Reboot button
If ISY is not online:
- Press the reset button inside the little hole on the front of the unit
- Or, unplug power and plug back in

Reset Username and Password to Defaults

Use a sharp object to push and hold in the Reset Button till the RX, TX, Mem, Error lights start blinking (every second)
Continue holding for another 5 seconds till the RX, TX, Mem, Error lights turn on/off consecutively (RX -> Tx -> Mem -> Error)
Release

There are only a very few reasons for performing a Factory Reset:

Corrupted File system (blinking ERR light)
- Also instead of a factory reset another option for corrupt file systems issues is Replacing/Formatting an SD Card
To start fresh ... i.e. if you are going to restore your old backup on the same ISY, then in all likelihood factory reset is NOT going to fix anything
Reuse one ISY for more than one location
You have configured your ISY with a static IP address, changed router/network, and can no longer access ISY

IMPORTANT: You must reconfigure ISY again or restore your backup after the factory reset.

Use a sharp object to push in the Reset Button till the RX, TX, Mem, Error lights start blinking (every second)
Hold for at least 30 seconds until all of the the RX, TX, Mem, Error lights turn off and Mem light starts flashing quickly
Release and wait for system reboot (reboot is complete when Mem light stops flashing)