go to www.microsoft.com. search for win 7 enterprise.u sud have email id from microsoft or its subsideries such as hotmail,live etc.choose right version for u 32 or 64 bit.microsoft will ask you details to fill. volaaa.....u will get link to download .just download & burn on dvd r/w or USB ...install on your system.now, activate it by using internet.whoppi, u have win 7 enterprise for 90 days.Enterprise version is equivalent to Ultimate version.it has all features which ultimate have......if u liked after 90 days,go and buy from online microsoft india store...its cheap there....ENjoy:)