Be careful when reloading some laptops now, though I have not seen this with ACER (But they may start) We sell acer's here but never have problems so we don't reload. But HP's and Dell's have company specific product key's for there windows. That said, if you reload windows with a regular Winodws 7 (or burned) Installation CD, even if you put in the product key, it will say it is correct, but when you go to Activate windows, it wont be valid.
This is because the key is only valid with the company's installation CD's or partition that was created.. Just a thought for people reloading preloaded systems..