Does anybody know if there s a software timer that can be set to turn PC off on scheduled time ?

For example in Nero software, there is an option "turn PC off when done"

Any program or a windows component that silly me not aware of ?

You could use Wizmo from http://www.grc.com/default.htm and schedule to run it at a certain time with the 'exit' parameter.

there is but most cost. the easiest and cheapest way is to use windwos scheduled task to run shutdown.exe (there some other parameters to)

*edit*
here be the full parameters

"RUNDLL32.EXE User,ExitWindows" for Windows 95/98/ME
"shutdown.exe -s -t 0" for Windows XP/2003, without the quotes

yeah id go with windows task scheduler

I like AutoClose

Windows Task Scheduler is teh best option