Modern computers should suffer no ill effects from being switched off after use, in fact. many programs and device drivers tend to develope faults if left running for long periods of time. Re-starting your computer has the effect of re-juvenating these programs/drivers.I recommend the computer be switched off each night before you retire and the power supply be turned off at the wall plug as even in stand-by mode it is possible that some weirdo will be able to remotely switch your computer back on and leisurely peruse your love letters or dirty pics.