hi i need an urgent help regarding dual booting.but just for some info,i want to tell u that i have windows vista ultimate x64 and windows 7 ultimate x64.Both are retail version,to which i apply crack to activate it.which works. this is the case in single OS installation. but i want to install both OS in my laptop.i have dell studio 1737. i want to install win7 as primary and basic os and vista as secondary os.i have tried doing it,by installing win7 on C driver and vista on D drive.then i apply crack to both of them one by one by booting in it.upon restarting, both OS has again reverted back to trial version. for this. *i have NOT defragmented C drive,i just simply installed win7 on C and vista on D. please tell me what way i do reinstall both OS that both keey working.