hello i have problem regarding vista online activation

i m using inspiron 1520

recently i had to reinstall my system

as i am not having original backup dvds(lost them while i moved from one house to another) i used msdn copy of vista downloaded thru net

after installation with my given key on the backside of my laptop copy installed was vista home premium which i choose when i bought my laptop

problem occured after that when i tried to activate with the microsoft online it gave me error message that

"the given key is already in use"

and it refused to activate

confusing thing is that i have never given the key to anyone

how do i solve the problem???

i want to actvate my vista

should i call customer care

how do i ask for backup cd from dell

i am from india and dnt seem to find page for backup cd request page

 

please help me out

any more info needed please reply i will surely provide

pls make hurry as 30 days limit of trial is about to over

 

thank you