Standby Button changed as disable

[Thamizhinpan]

I'm Using windows XP SP1.
When I installed it on computer I could able to standby computer.
But after I installed some software, stand by button changed as disable.
But i couldn't identify that particular software for this fault.
Can I enable this standby button again without reinstalling windows?

 

[cube_]

First make sure that the Hibernation is turned on.
Click Start > Control Panel > Power Options > Hibernate tab > check Enable hibernate support box > Apply/OK and then restart you computer.

If this doesnt solve it: In your BIOS, you should check to see if the ACPI/APM option is enabled. If it was disabled, enable it and follow the steps at the top.