BleepingComputer.com: starting up computer

due to having major alterations to our house my wifes pc has been off line, we had to store it away
now that our work has been completed we have tried to put her computer back on line .first of all it was fine ,worked straight away.
then the background pictur dissapeared leaving a black screen but still weorking.we closed it down and when we tried to open it again it keeps asking for an id code and then it tells me that my copy of vista is not genuine . i can assure you that it is .it is only just over a year old aND BAUGHT DIRECT from dell .can anyon help me please

hi,,, when it asks for the id code,,, try the product key,, on the laptop somewhere there is a greeny pinkish microsoft sticker with the product key on it,,, try entering this and see if this helps,,, if not contact dell and tell them that your os has shut down as its been flaged as a dodgey copy.