Windows has had the “autorun” feature for a while and its when windows looks for a disc in the drive that the light flashes.
It should not affect the sleep function at all. I have a system here that flashes the light in the same way but when it enters S3 suspend it all stops and the PSU shuts down without a problem. The system currently runs as an HTPC setup so goes on & off as it needs to.[/QUOTE]
I think OP meant the Hard drive light not light on ROM etc and even if you still mean what you said autorun is disabled on all my computers and mine has started to flash hd led every second very dim thought not as brightly lit as when full hd access is occurring.
I checked with perfmon %idle and it is still at 99.99% over 1 minute etc , but it does bug me that the hdd led is flashing very dimmly every second since adding either LG H20L or the 2 F1 samsung t/b drives.