We purchased norton antivirus 2005 single user edition,but it is not activating,we have a product ke

This could happen if you bought the software second-hand (in violation of the Terms of Use). And of course you need to be connected to the internet.

It happened to me once. Just call Symantec, and after waiting on hold for 30 minutes, they will sort it out. If you're in the U.S. the number's +1 800 441-7234.

We purchased norton antivirus 2005 single user edition,but it is not activating,we have a product key?bmw

It happened to me once. Just call Symantec, and after waiting on hold for 30 minutes, they will sort it out. If you're in the U.S. the number's +1 800 441-7234.

We purchased norton antivirus 2005 single user edition,but it is not activating,we have a product key?free adware remover

unistall norton and reinstall it.
If you have geniune product key and still its not activation they contact symantec

DONT SHARE YOUR PRODUCT KEY WITH ANYONE
Just try and ring them and they will probably tell you, the key has been used five times already and then you tell them to reactivate your key again because you are the legal owner of the software (provided you are the legal owner).
Contact Symantec, They will provide you a lisence file over e-mail. Only product key is not enough.
Norton Antivirus 2005 has a bug in is software.

and has been a problem for Symantec.

Harry