Thanks Ponmayilal & Neerajvohrs. We have not used windows activation tool but turn on automatic update. We are using BSNL Broadband connection and the updates install successfully. We did it yesterday i.e. 24th May night and till now 9 PM of 25th May, we have not faced any difference in our OS nor any warning from MS regarding our OS's piracy found. So we think the vendor (retailer) installed a Genuine OS. But anyway nice discussions and we assure all that if we get confirmation about our OS Piracy we will buy a genuine one whatever the price may be. As to clear u Ponmayilal, we have not asked the retailer to install Win 7, in fact we even did not know if the laptop would come preinstalled with any version of Window or Linux. We were really shocked to see the new and most wanted OS in our laptop.