When i switch on my pc the yellow light comes on but doesnt turn green

[polarzara]

Hello,
The power is coming through, but the green light doesn't come on so I can't use the computer. I seems to be in permanent sleep, or hibernation mode. How do I fix this please.

 

[ksiemb]

Hello,
The power is coming through, but the green light doesn't come on so I can't use the computer. I seems to be in permanent sleep, or hibernation mode. How do I fix this please.

I could be a power supply problem, or possibly corrupted OS.
Vista recovery Options
http://windows.microsoft.com/en-US/windows-vista/What-are-the-system-recovery-options-in-Windows-Vista

Do you use sleep/hibernate/standby on a regular basis ? I have never been in favor of using of it, as I have seen many many issues like this.