Where did you buy it? Where did you download it from?
How many digits are in the serial number you are trying to use?
You should know that you are NOT addressing Adobe here in these user-to-user forums,
brought from volume lic (website) download version. download from LWS website.
serial no. is retrieve from LWS website too... 24 digits
It´s called a CRACK (in plain english a conterfit version)
It most probably also came with a virus or a troian horse. Scan your computer for viruses!
You bought from pirates and you got robbed.
Do check your computer for malware, viruses and trojans.