Sleep or hibernation was not perfected in this OS. You may get it to work, but updated drivers, Windows Updates or other items may break it.
There isn't much support to be had for this issue so you find that disabling it and just letting the monitor power down is the common fix.
Bob
Occasionally my computer (Win98SE), when left alone, in 'sleep' mode (no screensaver), decides to reboot itself. It hasn't happened while I'm using it; just when I'm gone. It's running through a UPS, which I recently tested and found to be OK. Any suggestions as to what's happening? It has a new (less than 6 mos) power supply.

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