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This will be overwritten when SCCM gives the computer a power policy but this will prevent the computer from going to sleep if it's plugged into AC power. Laptops should never be imaged without AC power as they are unlikely to be compliant before they ran out of battery power.
Task sequence edit:
Add into the task sequnce to run the following code after installing the SCCM client and before installing Windows applications to ensure the computer doesn't go to sleep.
cmd.exe /c powercfg -x -standby-timeout-ac 0