Yes, I have the serial number (I have the original packaging that I bought it in with the serial number on it)
I entered the same serial number I used with laptop at the office.
I own the original program (disc)
If you have Lightroom 6 version installed on your computer then you would have an account with Adobe and should have registered the serial number in your account. The serial number is 24 numeric (6 tabs with 4 numbers. the first four will be 1160.
See the screen capture.
Lightroom 6 does not require a serial number to download you have to input the serial number after the install is done. The serial number is to activate the application.
Thank you so much for trying to help. I log into my adobe account. I have the serial number. When prompted I check it, the serial number is on the screen except for the last four digits xxxx. The problem is it starts to download and at a certain stage I receive a message that says it is a pirate copy - which it is not.